Most sensitive (9.01 pg/ml)  colorimetric ELISA for monitoring residual contamination.

• Highly sensitive measurement, detecting as little as 9.01 pg/ml (<1 ppm) of Protein A residuals in purified humanized mAb preparations
• Ensures accurate results as it recognizes several constructs of Protein A
• High throughput format with results in < 3 hours for up to 37 samples in duplicate
• Cost-effective solution compared to other technologies, providing a lowercost-per-test
• Useful for contamination analysis and measurement of Protein A variants in monoclonal antibody preparations

The Protein A EIA kit is a colorimetric immunometric enzyme immunoassay kit with results in < 3 hours. Absorbance is read at 450 nm. Ultra-sensitive quantification ( < 1 ppm ) of Protein A residuals in purified humanized monoclonal antibody preparations. This kit recognizes four different Protein A constructs.

Staphylococcus aureus Protein A is a 42 kDa cell wall constituent that is characterized by its binding affinity to the Fc portion of some immunoglobulins, especially the IgG class. The IgG binding domain (domain B) consists of three anti-parallel alpha-helices, the third of which is disrupted when the protein is complexed with Fc. Protein A is commonly used to purify antisera and in commonly used immunodetection and visualization techniques. Protein A participates in a number of protective biological functions including anti-tumor, toxic and carcinogenic activities, thus necessitating the removal of potential Protein A contaminants from antibody preparations for therapeutic use.