Protein Epitope Signature Tags (PrESTs)

PrEST Antigens™ are recombinant protein fragments originally developed as immunogens for generating our Triple A Polyclonals™ and PrecisA Monoclonals™. Beyond immunization, they serve as valuable control antigens—ideal for antibody validation, pre-adsorption assays, ELISA optimization, and assay QC.

Each PrEST Antigen corresponds to the exact sequence used for antibody production and is included in a rigorous three-step purification process to ensure high specificity and minimal cross-reactivity. Provided as a complement to our antibodies, they enable greater confidence, reproducibility, and traceability across your experiments.

Protein Type: Recombinant protein fragment, His-tagged
Expression System: E. coli
Purification: IMAC under denaturing conditions
Sequence Design: Low-homology regions to minimize cross-reactivity
Formulation: PBS with 20% glycerol
Purity: >80%, confirmed via SDS-PAGE
Volume: 100 µg standard (bulk on request)
 

Applications 

👉🏼 Antibody development and screening
👉🏼 ELISA and calibration standards
👉🏼 Western blot/IHC validation
👉🏼 QC reference controls
👉🏼 Specificity/sensitivity testing

Advance Your Assay Development with Antigens You Can Trust

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Why Prest Antigens™ 

Prest Antigens™ are ideal for scientists developing or validating antibodies in academia, biotech, and diagnostics. Use them to benchmark performance, reduce lot-to-lot variability, and enhance assay development workflows.

✅ Validated by the Human Protein Atlas and Atlas Antibodies–
✅ Biologically Relevant – Designed from Human Protein Atlas-verified sequences
✅ Low Cross-Reactivity – Minimal homology to other proteins
✅ High Purity – >80% purity confirmed
✅ Flexible Use – Compatible with IHC, ELISA, WB, and antibody screening

Explore the Prest Antigens™ catalog or contact our team to discuss how we can support your antibody development and assay workflows.

Designed for Specificity

The protein fragments are expressed as fusion proteins with a dual tag consisting of a hexahistidyl (His6) tag in frame with an immuno-potentiating Albumin Bin­ding Protein (ABP)-tag originating from Streptococcal Protein G.

The use of fragments of 50-150 amino acid residues facilitates cloning and protein expression and also provides conformational epitopes that could not be obtained using shorter peptides.

The 50-150 protein-specific fragments are selected using proprietary software to contain unique epitopes present in the native protein suitable for triggering the generation of antibodies of high specificity.

The high specificity is achieved by a complete human genome scanning to ensure that regions with the lowest homology to other human proteins are used as antigens for the generation of antibodies. In addition, signal peptides and membrane regions are avoided in the design.

Production, Validation and Quality Control

For cloning the PrESTs, a pool of RNA consisting of material from several human tissues is used in an RT-PCR approach. First, the amplified gene fragments are cloned and the sequence verified. Then, an E. coli recombinant protein expression system is used for expressing the clones, and the products are purified using nickel-containing matrices (IMAC).

The expressed PrEST Antigens are validated using ESI mass spectrometry. Purity is analyzed using the SDS page, and the PrEST Antigen amount is quantified using a Nanodrop system.