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Fast-Track Your PK Analysis with Automated Capillary Immunoassays

Simple Western™ is a fully automated capillary immunoassay. Separate proteins by capillary isoelectric focusing (cIEF) or capillary electrophoresis sodium dodecyl sulfate (CE-SDS) followed seamlessly by immunodetection directly in the capillary.

Reproducible quantification. Use CE-SDS to resolve proteins by size and quantify intact IgG, aggregates and fragments IC/EC50, LOD, LOQ, and more, with intra- and inter-assay CVs of <20%.

Add a Size- or Charge-base separation to your immunoassay. Use CE-SDS to resolve proteins by size and quantify intact IgG, aggregates and fragments. Use cIEF to quantify the main peak, acidic peak(s), and basic peak(s) of your antibody therapeutic.

No sample cleanup. Analyze highly complex samples like human serum without lengthy purification or concentration steps.

High throughput. Process up to 96 samples in one overnight run without user intervention.

High sensitivity. Highly sensitive immunodetection using as little as 3 µL of sample. Get up to 8 data points on the same 5 µL of sample. Multiplex to get more data points per sample with chemiluminescence and Stellar™ NIR/IR fluorescence detection with industry-leading sensitivity. Use RePlex™ to perform sequential immunoassays or Total Protein Detection on the same sample.

3-4 log dynamic range. Larger than ELISA.

Pharmacokinetic evaluation of therapeutic monoclonal antibodies and their biosimilars.

Simple Western Combines CE-SDS / cIEF with Immunodetection

  ELISA CE-SDS cIEF Simple Western
Immunodetection Yes No No Yes
Charge separation No No Yes Yes
Size separation No Yes No Yes

Quantitative Protein Characterization in Complex Samples

Simple Western on Peggy Sue™ combines the separation power of cIEF and CE-SDS assays with the sensitive and specific detection of an immunoassay. This combination places Simple Western in a unique position to study the PK properties of therapeutic monoclonal antibodies and their biosimilars.

Minimal matrix effects. Following cIEF/CE-SDS separation, proteins are immobilized to the capillary and thoroughly washed prior to immunodetection, flushing the remaining sample matrix out of the capillary. Thus, immuno-probing on Simple Western occurs in an idealized environment rather than within the sample matrix environment, reducing matrix interference that can plague ELISAs while also providing high-resolution charge/size separation. 

Sensitive immunodetection. Detect small amounts (low pg) of target protein with conventional Western blot antibodies.

Upstream and downstream workflows. Obtain comparable charge separation profiles in crude samples from early stages of product development with Peggy Sue and later stages of purified samples with Maurice cIEF. For more information, refer to our Protocol on Method Transfer between Maurice and Peggy Sue.

In this Application Note, Simple Western Charge and Size assays provided a complete picture of the PK activity of adalimumab in human serum. The Simple Western Charge assay provided the most wealth of information and was able to detect significant changes in the drug profiles over the course of the study, including the detection of unexpected stress-associated acidic peaks.

Bioprocess Workflow Solutions from Start to Finish

Look to us to provide top-quality instrumentation, reagents, and services for your protein bioprocessing. We offer an outstanding product selection and the flexibility to meet your specifications.

Take advantage of our:

  • Decades of experience in process development for cell culture and protein purification.
  • World class reagent and assay development.
  • Industry preferred technologies that simplify, automate, and advance protein analysis.
  • Proven record of customer satisfaction for bulk supply, custom solutions, and documentation.
  • Compliance with 21 CFR Part 11, ISO 13485:2016, USP <1043>, 21 CFR 820, and ISO 9001:2015 as applicable.
  • Absolute confidentiality
protein bioprocessing

Simple Western Applications

immune cells attack cancer cell



Transform your cancer & immuno-oncology research by utilizing next-generation Western blotting tools to give you richer views into your samples.

Solutions for Cell Signaling and Signal Pathways Analysis

Cell Signaling


Analyze entire signaling pathways with high sensitivity multiplexing and total protein normalization.

Testing for Lentivirus and AAVs

Cell and Gene Therapy


Next-generation analytical instrumentation to help improve and accelerate your cell and gene therapy workflows.

Advances in Targeted Protein Degradation

Targeted Degradation


Boost your screening studies using high throughput & hands-free Simple Western systems for quantitative analysis.

Biosimilar Antibodies Teaser Image

Pharmacokinetic Analysis


High-throughput pharmacokinetic analysis with quantitative, high-sensitivity assays directly in complex lysates and tissue homogenates. 




A validated workflow for protein analysis in extracellular vesicle samples from the leaders in exosome isolation and high sensitivity Western blotting solutions.

Vaccine development image

Vaccine Development


Improve reproducibility, quantitation, and time to market for your vaccine candidates.

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Increase your sensitivity and multiplexing capabilities with neural samples using automated Western blotting systems.

Simple Plex HEK-HCP Assay

Bioprocess Impurities


Screen for processing-related impurities and host-cell related contaminants. Quantify empty/full capsid content of viral vectors like AAVs.


SARS-CoV-2 Research


Reduce your lab time while accelerating your COVID‑19 research. Set up, leave and remotely review your data in just 3 hours!

SARS-CoV-2 Serology

SARS-CoV-2 Serology Assay


Rapid quantitative characterization of human IgG antibodies in serum or plasma reactive against multiple SARS-CoV-2 antigens.