Each antibody is developed against a recombinant human Protein Epitope Signature Tag (PrEST), typically 50–150 amino acids in length.
These PrEST sequences are carefully selected to have minimal sequence similarity to other human proteins, significantly reducing the risk of cross-reactivity.

To assess specificity and purity, all antibodies are tested using a protein array containing 364 human recombinant protein fragments. This step ensures target selectivity before functional testing.

Our Triple A Polyclonals and PrecisA Monoclonals undergo functional validation in the most common antibody-based assays, including:

• Immunohistochemistry (IHC)
• Immunocytochemistry–Immunofluorescence (ICC–IF)
• Western blot (WB)
• Chromatin Immunoprecipitation ChIP

For IHC, each antibody is evaluated in a broad panel of tissues, including 44 normal human tissues and the 20 most common cancer types. Performance is documented with over 500 high-resolution staining images per antibody, reviewed and annotated by expert researchers and pathologists. These images are available via the Human Protein Atlas.

Antibody specificity is further assessed through a combination of literature review, bioinformatics analysis, and comparison to RNA sequencing data to ensure biological relevance.

All validation data, including images and experimental conditions, are freely available on the Atlas Antibodies and Human Protein Atlas websites.
We also provide the exact immunogen sequence used for antibody generation, giving you complete insight into how each reagent was developed.

While both validation and reproducibility are essential for antibody quality, they address distinct aspects of performance:

Validation ensures that an antibody specifically binds to its intended target. Before any antibody is added to our catalog, it undergoes extensive validation. All validation data are documented and included on the antibody’s product data sheet.
Reproducibility refers to the ability of an antibody to perform equally across different production lots. It ensures that a new batch behaves in the same way as the previous one, across all validated applications.

To guarantee reproducibility, each new antibody lot is tested against a reference lot. The comparison includes performance in all relevant applications (e.g., IHC, WB, ICC–IF), ensuring that the specificity and functionality remain consistent.

This process allows us to maintain lot-to-lot consistency and provide researchers with reliable antibodies they can trust across long-term projects.

The standard test set-up for quality control of an antibody for the IHC application at Atlas Antibodies consists of a tissue microarray of more than 20 different samples of both normal and cancer tissues. The new lot of the antibody is tested and compared to the reference lot on consecutive sections from the tissue microarray.

As the original manufacturer of all our products, we have full control of both the validation and reproducibility. You can trust that our antibodies are specific and perform consistently each time you use them.

The image show examples from the quality control of antibody Anti-SATB2 (HPA001042) where a new lot is tested against its reference lot: IHC staining of human cerebral cortex, colon, liver and rectum using Anti-SATB2 antibody HPA001042 (A) shows similar protein distribution across tissues to independent Anti-SATB2 antibody HPA029543 (B).