Simple Western technical library

The epidermal growth factor receptor (EGFR) is a transmembrane receptor for the epidermal growth factor family (EGF-family) of extracellular protein ligands. Ligand binding activates its intracellular tyrosine kinase domain resulting in auto as well as substrate phosphorylation. Mutation and deregulation of EGFR is implicated in many cancer types. The data shows a time dependent change in anti-phospho EGFR (Y1068) antibody signal in HeLa cells in response to EGF treatment.

The p21 activated kinases (PAK) proteins are a family of serine/threonine kinases that serve as targets for the small GTP binding proteins, CDC42 and RAC1, and have been implicated in a wide range of biological activities. PAK2 is a member of the PAK subfamily 1 including PAK1 (α-PAK), PAK2 (γ-PAK, PAKθ, hPAK65), and PAK3 (β-PAK). The kinase domains within a subfamily show a high degree of sequence identity, and all PAK proteins bind GTP-bound Rho family members at the amino-terminal p21-binding domain (PBD). Our data in HeLa cells show a pattern of 5 peaks using a pan PAK1/2/3 antibody of which two are picked up consistently by 3 different specific PAK2 antibodies identifying them as PAK2 peaks.

GSK3 is a critical downstream element of the PI3 kinase/AKT cell survival pathway whose activity can be inhibited by AKT-mediated phosphorylation at Ser21 of GSK-3α and Ser9 of GSK-3β. While GSK-3α and GSK-3β have high sequence homology, their biological function differs. The data presented shows an increase of peaks detected by anti-phospho GSK-3α antibody as well as an increase of the same peaks detected by the total anti-GSK-3α antibody in response to EGF treatment in MCF10A cells. At the same time, the peaks not recognized by the anti-phospho Ser21 antibody decrease in size, implying that these peaks represent non-phospho or non-pS21 phospho GSK-3α forms. The position of these peaks around pI 9 is in accordance with the theoretical pI for this sequence. In other cell systems (A549 for example), both the anti-total GSK-3 antibody as well as the anti-phospho GSK-3α antibody also recognize peaks around 6.0. Alignment of the GSKα and GSKβ profiles in addition to use of antibodies recognizing both isoforms confirmed the specificity of the anti-GSK-3α versus the anti-GSK-3β antibodies used (data not shown).

Thioredoxin acts as an antioxidant and is found in nearly all known organisms. It exists in two isoforms and presents a double peak around pI 4.6. The data presented show the utility of Thioredoxin as a loading control for EGF treated A549 and HeLa cells.

The 70 kilodalton heat shock proteins (Hsp70) are a family of ubiquitously expressed heat shock proteins. Proteins with similar structure exist in virtually all living organisms. The Hsp70s are an important part of the cell's machinery, and help to protect proteins from misfolding under stress. We describe its use as loading control for EGF stimulation in HeLa and MCF10A cells. In the NanoPro assay, Hsp-70 is present as a single peak around pI 5.8 under the conditions described.

β-2-Microglobulin, also known as B2M, is a component of MHC class I molecules, which are present on all nucleated cells. In the NanoPro assay, it presents a single peak around pI 6. The data show its application as a loading control for EGF stimulation in HeLa cells as well as MCF10A cells.

The Signal Transducer and Activator of Transcription (STAT) proteins regulate many aspects of cell growth, survival and differentiation. The transcription factors in this family are activated by Janus Kinase (JAK). Dysregulation of this pathway is frequently observed in primary tumors and leads to increased angiogenesis, enhanced survival of tumors and immunosuppression. STAT5 is constitutively active in the overexpressing BCR-ABL K562 myelogenous leukaemia cell line. Imatinib (also known as Gleevec®), a BCR-ABL inhibitor, reduces STAT5 phosphorylation in these cells. STAT5 is also part of the Epidermal Growth Factor (EGF) signaling cascade as shown in MCF10A cells.

Extracellular signal-regulated kinases (ERK) or classical MAP kinases are widely expressed intracellular signaling molecules involved in regulation of meiosis, mitosis, and post-mitotic functions in differentiated cells. Many different stimuli (including growth factors, cytokines, virus infection, ligands for heterotrimeric G protein-coupled receptors, transforming agents, and carcinogens) activate the ERK pathway. We show an example of ERK phosphorylation in MCF10A cells in response to treatment with epidermal growth factor (EGF).

Dual specificity mitogen-activated protein kinases (MEK) are members of the dual specificity protein kinase family, which act upstream from the classical MAP kinases through phosphorylation and thus activation of ERK1 and 2 in response to a wide variety of extra- and intracellular signals. While the functions of MEK1 and MEK2 are very similar, theses kinases differ significantly in the way they are regulated. For example, serum addition can specifically induce MEK1 activity in CHO cells. By contrast, MEK2 appears to be the functionally predominant isoform in formyl-methionyl-leucyl-phenylalanine treated neutrophils. Here we show MEK2 activation in MCF10A cells in response to EGF stimulation.

c-Jun N-terminal kinases (JNK), originally identified as kinases that bind and phosphorylate c-Jun on Ser63 and Ser73, are mitogen-activated protein kinases which are responsive to stress stimuli, such as cytokines, UV-irradiation, heat shock, and osmotic shock, and are involved in T cell differentiation and apoptosis. JNK1, 2 and 3 share a total of 10 isoforms with pI's ranging from 5.4-7.6. All three JNK kinases share a similar Thr/Tyr phosphorylation site (T183/Y185). We evaluate change in JNK phosphorylation in UV-treated HEK293 cells and imatinib-treated K562 cells using a dual phospho-antibody against that site.

Translation repressor protein 4E-BP inhibits cap-dependent translation by binding to the eIF4E translation initiation factor. Hyperphosphorylation of 4E-BP disrupts this interaction and results in activation of cap-dependent translation. Both the PI3 kinase/Akt pathway and FRAP/mTOR kinase regulate 4E-BP activity. 4E-BP1 has been implicated as a biomarker for several cancer types, while 4E-BP2 has been shown to potentially play a role in energy homeostasis. We show 4E-BP1 activation in MCF10A cells in response to EGF using total and anti-phospho 4E-BP1 antibodies that enable distinction between phospho and non-phospho peaks.

Crk-like protein (Crk-L) is an adapter protein and phosphotyrosine-containing substrate implicated in transformation by the bcr-abl oncogene and in signaling by cytokines. It has been shown to activate the RAS and JUN kinase signaling pathways and transform fibroblasts in a RAS-dependent fashion. Crk-L is a substrate of the BCR-ABL tyrosine kinase and plays a role in fibroblast transformation by BCR-ABL. We show that Crk-L phosphorylation is reduced in response to Imatinib (commonly known as Gleevec®) treatment in K562 cells.

Epitope tags are widely used for afinity purification as well as for highly sensitive detection of recombinant proteins. The FLAG-tag
consists of a short peptide sequence (MADYKDDDDKM). EGFP was expressed with a FLAG-tag at either the C- or N-terminus of the
protein. As expected from the amino acid composition of this tag, a slight acidic shift in the pI of the tagged protein can be observed.

The enzyme-drug, L-asparaginase, has been used since the 1970s to treat acute lymphoblastic leukemia. Asparagine synthetase (ASNS) expression has been found to be correlated with L-asparaginase efficacy in leukemia cell lines, in leukemia primary tumor samples, and more recently, in cancer cell lines from other tissues of origin. Silencing ASNS expression by RNAi has indicated the L-asparaginase/ASNS relationship is causal and suggests that ASNS expression may be useful as a predictive clinical biomarker of L-asparaginase efficacy. ASNS presents as a single peak in the NanoPro assay. Expected changes of expression are observed upon siRNA as well as L-asparaginase
treatment.

cIAP1 is a member of the inhibitor of apoptosis (IAPs) family of proteins. It is up-regulated in several human cancers and plays an important role in tumor survival. cIAP1 functions to prevent cellular apoptosis by preventing the activation and/or inhibiting the function of different caspases.

Eukaryotic elongation factor-2 (eEF2) catalyzes ribosome translocation during translation of mRNA. Phosphorylation of eEF2 by eEF2 kinase (also known as CaM kinase III) inactivates the protein and can block protein synthesis. Stimulation of growth is associated with a decrease in eEF2 phosphorylation. Inhibition of eEF2 phosphorylation in the hippocampus has recently been associated with an anti-depressant eect. We show that insulin treatment reduces phosphorylation of eEF2 in H4IIE cells. Inhibition of phosphorylation of eEF2 is restored in the presence of Nh125.

Mitofusin 1 (Mfn1) and Mitofusin 2 (Mfn2) are two highly homologous mitochondrial outer membrane proteins necessary for mitochondrial fusion. Mitochondrial fusion is necessary to maintain mitochondrial health and function, and mitochondrial dysfunction is implicated in diseases such as Charcot-Marie-Tooth 2A and dominant optic atrophy, as well as in multiple tissue types. Phosphorylation of these proteins has not been widely studied. Our data show detectoin of Mfn2 protein in three neuronal tissues: retina, optic nerve, and the superior colliculus region of the brain in a mouse model, DBA/2J, a widely accepted model for glaucoma.

The Mitogen Activated Protein Kinase p38 is activated by stress stimuli such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, and are involved in cell differentiation and apoptosis. We show that Interleukin-1 (IL-1) treatment induces phosphorylation of p38 in fibroblasts. In addition, two independent antibodies recognize peaks at pIs 5.4 and 5.8 for phosphorylated p38.

Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a tumor suppressor protein that is frequently mutated or deleted in many tumors. PTEN dephosphorylates phosphatidylinositol 3,4,5-triphosphate (PtdInsP3) inhibiting phosphoinositide 3-kinase (PI3K) activation of AKT repressing cell growth, proliferation and survival. Recent studies show that PTEN phosphorylation alters its stability and function.

Acetylation is a common post-translation modification typically observed on chromatin proteins as well as other regulatory proteins and metabolic enzymes. The reaction is catalyzed by N-terminal acetyltransferases, occurs predominantly during protein synthesis and appears to be irreversible. Pan-Ac-Lysine antibodies are widely used for detection of acetylation of imunoprecipitated proteins when no specific antibodies are available.

シンプルウェスタンTotal Protein Assayの同時測定で、イムノアッセイデータのノーマライゼーション

Simple Westernでバイオプロセス中の不純物質の検出
医薬品製造過程関連の不純物の同定および定量

In drug discovery, confirmation of in-cell target engagement is a critical component of the drug development process. Confirming that a drug candidate engages its proposed target in the cell and determining the concentration at which it exerts the desired effect(s) fulfill fundamental criteria for translation to activity and efficacy in its target tissue. Thermal shift assays (TSA) are regularly used by industry and academia to uncover or confirm interactions using purified proteins. Recently, this type of assay has been adapted to a cellular format and is called the cellular thermal shift assay (CETSA). In this application note, quantitative and reproducible CETSA data generated with ProteinSimple’s Wes instrument (CETSA-Wes) are presented. This assay verifies drug target binding, and given its quantitative nature, the half maximal inhibitory concentration (IC₅₀) is also calculated.

In this application note, we’re honing in on the biomarker verification and validation steps. Proof-of-concept data was generated to demonstrate how Simple Western and Simple Plex assays data give similar trends and work together to give you fast, sensitive, and precise information about your biomarkers of interest.

Scientists measure serum antibody levels to confirm immune responses against a bacteria to diagnose infections, to test for antibody production after vaccination, and to detect the presence of autoantibodies in autoimmune diseases. Traditional Western blots are often used to detect these antibodies, but testing with Western blots means a lot of hands-on time. After the antigen of interest is separated by SDS-PAGE and transferred to a membrane, each lane has to be cut into individual strips so patient serum samples can be individually tested for the presence of specific antibodies. Then you have to process and analyze them manually.

Simple Western assays happen in individual capillaries, and everything from sample separation to data analysis is completely automated. No more cutting individual strips, washing and incubating them, or lining them all up with a molecular weight marker before detection. Just pipette your sample into the wells of your assay plate, set up your run, and you're done! And all that manual data analysis is gone too — Compass for Simple Western does it all for you. Did we mention you only need 10 µL of diluted serum per data point? That means you'll get a lot more data points for every 1 µL of neat serum.

In this application note, we used Simple Western to detect autoantibodies in lupus patient serum as a model system to generate proof-of-concept data for the assay. But you can use this method any time you need to detect and quantitate specific serum antibodies. In fact, check out how researchers are using this assay to detect Salmonella antibodies without having to cut blots into individual strips.

Peggy enables researchers to follow up a size-based immunoassay with a charge-based assay on one platform using the same sample. The charge-based analysis provides an information-rich, complementary data set, elucidating ratios of protein variants and providing leads for biomarker development. Like other Simple Western products, Peggy provides a fully automated solution, from loading samples
all the way to peak analysis.

Monophospho- and diphospho-ERK isoforms are not resolved by traditional Western blot analysis, and the sample quantity required is relatively large. The Firefly ERK1/ERK2 assay can distinguish and quantify unphosphorylated, mono and dual-phosphorylated isoforms of ERK1 and ERK2, allowing a more accurate determination of ERK activation than Western blots provide.

This document supports the use of Simple Western™ systems (Wes™, SallySue™, PeggySue™ and NanoPro 1000™) in a Quality Control (QC) and Good Manufacturing Practice (GMP) environments. All functionality is integrated in Compass for Simple Western software (version 2.0 and above) for compliance with 21 CFR Part 11. The information presented assumes that the appropriate system configuration parameters have been set.

Electrophoresis eBook

In this eBook, we examine technological advances in protein analysis that are at the forefront of immuno-oncology research and therapeutic development.

Research into prevention and treatment of disorders of the brain and nervous system are in greater demand as the world’s population expands. This group of diseases result in more hospitalizations than any other group, including heart disease and cancer. Odds are that you know someone affected by a neurological disorder, as The World Health Organization estimates that one billion people are affected by them, contributing to 11% of the world’s disease burden.

Proteins are the heart and soul of functional biology and understanding proteins is central to understanding disease. However, proteins are difficult to interrogate because they are large, complex, and unique. Here at ProteinSimple, we believe that traditional protein analysis tools can be overly complex or inadequate, and our goal is to make protein analysis simpler, more quantitative, and affordable. Ultimately, we want to help researchers gain a better understanding of proteins and their role in disease.

“[Wes] Provides quantitative data, saves time and uses far less sample.”

"Some of the proteins we wanted to detect are low in abundance and it's really hard to get a good amount of protein for traditional Western blot. The low protein concentrations required by Wes makes it easier to save precious samples ensuring protein detection."

“We’ve been able to increase productivity dramatically with Wes. The results are much better too, given that it removes the blotting step all together.”
— Melyssa Bratton, Ph.D., Manager of the Cell, Molecular, and Biostatistics Core, Xavier University of Louisiana

"The Simple Western Charge assay, a capillary isoelectric focusing immunoassay, exceeded the reliability of 2D Western blots for resolving recombinant PKG-Iα and PKG-Iβ and uses 100,000X less sample quantity, making it well-suited for clinical disease proteomics because protein isoforms and post-translational modifications can be detected in precious tissue biopsies."
— Mary G. Johlfs, M.S., Director of Research Operations/Scientist, Roseman University of Health Sciences

“The traditional blotting method can use up to 300 pieces of plastic and Wes uses two. What’s even better is that Wes can run up to 40 proteins in three days. It would take about a week to run 40 proteins using Western blotting.”
— Jamie Boisvenue, Cardiovascular Research Technician, Department of Pediatrics, University of Alberta Faculty of Medicine & Dentistry

"The rapid, reproducible results on small amounts of tissue/cell lysates have allowed me to generate a more thorough data set on additional proteins, samples, conditions and brain regions all in the same amount, or even less time, as traditional Western blot. This technology has made it possible for small research labs to compete with the pace that research is conducted in large labs or companies."
— Miranda Orr, Ph.D., Postdoctoral Fellow, University of Texas Health Science Center

We want to keep you updated on all of our advances in protein discovery and analysis, so here is our quarterly newsletter. It's never been easier to see what we're up to because each page covers a product platform and, if you want to attend an event, all you have to do is click on it to register. From new application notes and publications to product updates, we've got you covered.

Multiple myeloma has been comprehensively analyzed using high-throughput genomic technologies. Although a large number of biomarkers have been described, most of them were not subsequently validated at the protein level. In fact, the unresolved difficulties in studying the proteome have made the quantification of messenger RNA (mRNA) an indirect measure of protein expression. However, many studies have shown that levels of mRNA cannot be used as surrogates for protein levels. The amount of myeloma cells obtained after purification of patient samples is usually very limited, which precludes the possibility of quantify protein levels using standard Western Blot analysis.

Congenital infection of human cytomegalovirus (HCMV) is one of the leading causes of non-genetic birth defects, and development of a prophylactic vaccine against HCMV is a top priority for public health. The gH/gL/pUL128-131 pentameric complex mediates HCMV entry into endothelial and epithelial cells, and it is a major target for neutralizing antibody responses. To better understand the mechanism by which antibodies interact with the epitopes of the gH/gL/pUL128-131 pentameric complex resulting in viral neutralization, we expressed and purified soluble gH/gL/pUL128-131 pentameric complex and gH/gL from Chinese hamster ovary cells. Our results highlight the importance of the gH/gL/pUL128-131 pentameric complex in HCMV vaccine design and emphasize the necessity to monitor the integrity of the pentameric complex during vaccine manufacturing process.

Amyotrophic lateral sclerosis (ALS) is a devastating and fatal neurodegenerative disease of adults which preferentially attacks the neuromotor system. It has been shown that Amyloid-beta (Aβ) levels are elevated in spinal cords of late-stage superoxide dismutase 1 (SOD1) G93A mice (model of familial amyotrophic lateral sclerosis [ALS]) and that Aβ peptide(s) were localized predominantly within affected motor neurons (MN) and surrounding glial cells. Moreover, neuromuscular junction (NMJ) loss and MN degeneration were reduced in SOD1 mice when APP was genetically ablated, suggesting that endogenous APP actively contributes to the pathophysiology of this form of ALS.

Additionally, Aβ and glutamate have been physiologically found in NMJs. Previous work done in our lab, showed the tight relationship between glutamate and Aβ in the NMJ. We showed that an interconnection between glutamate and Aβ peptide, as demonstrated in cortical and hippocampal neurons, is also operating in nerve-muscle co-cultures (Combes et al., 2015).

Here, using a nerve-muscle co-culture system, we studied the toxicity of Aβ and the mechanisms involved in the process of NMJ death. The aim of this study was to investigated the role and the mechanism of Aβ on an in vitro model of functional NMJ.

Alzheimer disease (AD) affects mainly people over the age of 65 years, suffering from different clinical symptoms such as progressive decline in memory, thinking, language, and learning capacity. The toxic role of beta amyloid peptide (Ab) has now shifted from insoluble Ab fibrils to smaller, soluble oligomeric Ab aggregates (AβO). Many evidences suggest that the neurodegenerative process would be due to the interaction of AβO with binding targets, activation of stress kinases, hyperphosphorylation of tau protein, caspase activation, loss of synapse, neuronal death, loss of cholinergic function, generation of reactive intermediates of oxygen (oxidative stress), or glutamate excitotoxicity. Urgent need for efficient new therapies is high, but could only be successful with an extensively comprehension of AβO degeneration process. In the present work, based on an in vitro primary cell culture treated with AβO preparation, we have carefully studied the cytopathological effects of AβO on neuronal death and then we have investigated the effect of 17-beta Estradiol (β-estr) on the degeneration process induced by AβO. Briefly we used rat cortical neurons (from E15). The cells were seeded in 96-well plates and intoxicated with AβO solution after 11 days of culture for 24 hours. β-estr was used at 100 nM (final concentration) and was added as pretreatment (1h before injuries). A co-incubation with selective inhibitors was performed for the mechanistic study. In parallel, western blotting (WB) analysis was done to quantify protein levels and their activation. We showed that β-estr was able to significantly protect neurons as well as glial cells from degeneration decreasing the caspase 3 activation and the massive mitochondrial stress (induced by AβO). Preservation of neurite network and synapsis integrity was also observed. Moreover, the large hyperphosphorylation of tau protein induced by AβO was significantly reduced with β-Estr. A mechanistic study was also performed co-incubating inhibitors of main survival pathways to try to better understand the mode of action of β-estr and the pathway involved in the AβO toxicity. We showed that the effects of -Estr were fully abolished blocking the MEK pathway as well as the DNA repair pathway (PARP-g) or the mitochondrial anti-apoptotic pathway (Bcl2). Interestingly the effect was inexisting coincubating β-estr with TrK receptor or Ras/Raf inhibitors showing the predominant role of growth factors paythway in its neuroprotective effect. Finally, we showed a large inactivation of AKT protein in presence of AβO that was reversed even over activated in presence of β-Estr.

Targeted anti-cancer therapy using small molecules or therapeutic antibodies is important to improve the treatment options of individual cancer patients whose tumor show specific expression patterns of respective target proteins. In order to enhance the development of new targeted drugs, novel and highly predictive in vitro drug testing models are needed which closely reflect the characteristics of each individual tumor.

Towards this end, Indivumed has developed a preclinical drug testing platform based on freshly cultivated tumor tissue slices which enables a detailed investigation of functional effects of classical chemotherapeutic drugs, small molecules and therapeutic antibodies in a natural tumor microenvironment. In addition, this multifunctional in vitro model permits the evaluation of target expression and analysis of signaling pathway activities.

The aim of the present study was to analyze and verify the functionality of an anti-EGFR antibody in colorectal cancer tissue slices using our recently developed drug testing platform. As readout of treatment effects changes in the expression and phosphorylation status of selected signaling proteins from two EGFR-related downstream pathways, the MAPK and Akt pathways, were evaluated by Meso Scale Discovery (MSD) assays and immunohistochemistry. To further analyze the complex regulation of phosphorylation pattern in more detail, we integrated the new NanoPro 1000 technology in our pathway analysis, enabling the identification of distinct isoform phosphorylations. This approach should help to extend the knowledge about individual drug responses among patients to further advance
personalized medicine.

Background: Signaling from the IGF1R plays a role in resistance to anti‐cancer therapy in HNSCC. Thus, targeted inhibition of the IGF1R holds substantial therapeutic potential. While several inhibitors of the IGF1R are in clinical trials, there is no biomarker that predicts tumor responsiveness to anti-IGF1R therapy. Such a predictive biomarker is likely to be a component of the most prominent downstream signaling cascades from the IGF1R, which include the MEK/ERK or PI3K/AKT pathways that principally regulate proliferation and survival, respectively.

Hypothesis: Short‐term changes in the activation status of downstream signaling proteins will be predictive of long‐term tumor response to inhibitors of the IGF1R, and these changes will be detectable in minimal tissue samples using NIA technology.

Aberrant expression and signaling in the EGF signaling cascade is a common occurrence in a variety of cancers including breast cancer. Understanding how EGF signaling impacts disease progression is key to the development of novel therapeutics. Analysis of ERK1/2 and 4E-BP1 expression in cancer samples frequently employs Western blot analysis. In-depth phosphorylation analysis often requires 2D gels which are extremely variable and labor intensive, followed by MS analysis. In this study, novel, capillary-based technologies by ProteinSimple are used to evaluate changes in signaling proteins. Size-based as well as charge-based separation techniques were utilized, each of which is followed by immunoassay detection.

We present data comparing analysis of key targets of the AKT signaling cascade via Western blot and Simple Western on Simon, highlighting workflow, biological response, sensitivity, and resolution.

We present the development of novel nanoimmunoassays for the translational repressor proteins 4E-BP1 and 4E-BP2 using NanoPro technology. Both the PI3 kinase/Akt pathway and FRAP/mTOR kinase pathway regulate 4E-BP1 activity, making 4E-BP1 a focal point for these two important signaling pathways. 4E-BP2 regulation is poorly understood, partially due to the lack of specific anti-phospho 4E-BP2 antibodies. Our assay, developed on the Cell Biosciences NanoPro platform, enables detailed differential investigation of 4E-BP1 and 4E-BP2 phosphorylation and signal transduction.

To fully enable the vision of 'bench-to-bedside' requires the development of not only novel therapies, but novel techniques for evaluating their efficacy in cell lines, animal models and primary tumor material. This report describes our development of a technique employing a nanoimmunoassay platform for the analysis of signaling protein activation in primary non-small lunch cancer (NSCLC) solid tumors.

Activation of the MAPK pathway involves a complicated web of MEK phosphorylations. The two MEK isoforms are regulated by at least 3 other enzymes — PAK, RAF and ERK. Up until now it has been impossible to quantitate and determine the stoichiometry of the various multiply phosphorylated MEK forms. We have developed a new capillary immunoassay which resolves the different MEK variants, and allows measurement of the relative abundance of each form with a single antibody. This measurement of how the multiply phosphorylated forms change gives insight into how the dynamics of pathway feedback and activity change in response to drug treatment.

We have shown that signaling upstream of MEK kinase is inhibited by negative feedback in tumor cells in which the pathway is driven by HER kinases. In these cells, MEK1 is phosphorylated at ERK-- and PAK-dependent sites (T292, S298), whereas phosphorylation on RAF-dependent sites is undetectable. A selective MEK inhibitor inhibits ERK phosphorylation, relieves the negative feedback and activates MEK phosphorylation in these cells. Under these conditions, phosphorylation of both kinases on the RAF dependent sites (S217, S222) is markedly induced. Thus, inhibition of MEK/MAPK signaling in these cells abrogates upstream feedback of the pathway and results in a complex change in phosphorylation of MEK due to multiple kinases.

The capillary immunoassay allows determination of complex changes in phosphorylation of MEK kinase by PAK, RAF and ERK kinases in response to MEK inhibition. This technique will be useful in mapping pathway network response to targeted drugs in vitro and in vivo.

A recent wave of anti-cancer compounds that target tyrosine kinases (TKIs) has been moving through the drug development pipeline. Assessment and screening of lead compounds in simple model systems is relatively straight forward. Until recently, however, determining the impact of these compounds in complex biology of patient-derived cells and tissues has been diffcult. Proposed genetic or protein biomarkers can act as surrogates to a response, but measuring the signaling pathway in both the target cells and surrounding normal tissue will provide a more direct metric. This has proven diffcult due to the limited nature of primary material and complexity of tissue structure. Here we describe a novel nano-immunoassay platform (Firefly™) that has two significant advantages over traditional immunoassays: (1) extremely sensitive protein detection, and (2) physical isoform separation, which allows for quantitation of protein isoforms as well as post-translational modifications such as phosphorylation.

Applications of this technology that will be described include:
1. Effect of TKIs on signaling in punch biopsies of non-small cell lung cancer cells
2. Signaling pathway response from chronic myleogenous leukemia patients to therapies targeted to the bcr/abl translocation

これらのDetection Moduleは、Separation Moduleと一緒に使用し、分子量に基づいた シンプルウェスタンで1次抗体を用いてターゲット分子を検出するのに必要なすべて の試薬を含んでいます。

これらのDetection Moduleは、Separation Moduleと一緒に使用し、分子 量に基づいたシンプルウェスタンで、抗体を用いてターゲット分子を検 出するのに必要なすべての試薬を含んでいます。

Product Insert: Jess Training Kit

ブロットカートリッジを用いてJessでブロットイメージング
クイックリファレンスガイド

Blot imaging on Jess using the blot cartridge Quick Reference Guide

A previously undescribed isoelectric focusing technology allows cell signaling to be quantitatively assessed in <25 cells. High resolution capillary isoelectric focusing allows isoforms and individual phosphorylation forms to be resolved, often to baseline, in a 400-nl capillary. Key to the method is photochemical capture of the resolved protein forms. Once immobilized, the proteins can be probed with specific antibodies flowed through the capillary. Antibodies bound to their targets are detected by chemiluminescence. Because chemiluminescent substrates are flowed through the capillary during detection, localized substrate depletion is overcome, giving excellent linearity of response across several orders of magnitude. By analyzing pan-specific antibody signals from individual resolved forms of a protein, each of these can be quantified, without the problems associated with using multiple antibodies with different binding avidities to detect individual protein forms.

ＨＤＲはHigh Dynamic Range(高いダイナミックレンジ)を表します。写真撮影においては最初に露出を変えながら複数の画像を撮影した後で、特殊なアルゴリズムを用いて、これらの画像のベスト部分を組み合わせて自動的に最良のイメージを作成します。 SimpleWestern®のＨＤＲも同様なアルゴリズムに基づいています。 ダイナミックレンジが広がると、貴重なサンプルを無駄にしたり、アッセイの最適化に多くの時間を取られることもなくなります。アッセイの最適化の時間を短縮するために、アッセイの検出ステップとデータ解析の両方を強化するＨＤＲ検出プロファイルを利用してWesのダイナミックレンジを拡大しました。

Jess, the newest Simple Western™ technology from ProteinSimple, allows you to not only run fully automated capillary-based Westerns, but she takes digital images of traditional chemiluminescent Western blot membranes. ProteinSimple’s AlphaView® software allows you to analyze Western blot images taken on Jess so that you can prepare publication-ready figures. In this tech note, we’ll show you how to export your images from Jess into AlphaView, and we’ll cover the tools that you’ll need to get the most out of your Westerns.

If you’re experiencing primary antibody derived cross reactivity with the 230 kDa protein used as one of fluorescent standards, we’ve got a solution.

In this technical note we show you how this new assays works and give you a couple examples comparing Simple Western performance with traditional Western.

Multiplexing two targets in one capillary with Simple Western doubles the number of data points per sample and increases the data quantitation accuracy when you normalize to biological loading control or system control.

When you're ready to start multiplexing, first optimize the primary antibodies separately to find the saturating dilution for each. Then combine them in Antibody Diluent 2 to detect the two targets in the same capillary. If the primary antibodies are raised in two different host species, you'll also need to combine two different anti-species secondary antibodies. But mixing Ready-To-Use (RTU) secondary antibodies will dilute them and cause the signal to decrease or become more variable because they're no longer saturating. We've got the situation under control with the 20X Anti-Rabbit HRP Conjugate.

An immunoassay with a large dynamic range lets you simultaneously see really high and really low signal at the same time. This means not needing to spend time either diluting or concentrating your samples to get your protein of interest in the detected dynamic range. Wes® has always been great at detecting really low levels of protein and now we’ve improved what you’ll see on the high end, giving you at least one more log in dynamic range compared to a Traditional Western blot.