ELISA Kit for the quantitative Measurement of Pichia Yeast HCP Residues in Culture Supernatants, Protein Purification Process, and End-Product

**1. APPLICATION**

The kit is intended for the quantitative determination of host cell protein residues in Protein therapeutics expressed by Pichia Yeast expression systems.

**2. BACKGROUND**

Pichia Yeast, commonly is widely utilized as an expression of therapeutic proteins. The process of expressing target proteins, undergoing concomitant apoptosis, which release up to a thousand of host proteins into cell culture medium after the break of cells. These host proteins exhibit strong immunogenicity, which can lead to adverse toxicity or immune reactions, jeopardizing product safety and quality, and causing potential biological contamination. One of the aims of downstream processes in the production of biological medicinal products is to remove these potential hazards.

Therefore, it is essential to minimize the residual levels of host cell proteins (HCP), and in the downstream purification process development, a scientifically sound method for determining the concentration of HCP in finished or semi-finished products is necessary. Enzyme-linked immunosorbent assay (ELISA) has a high sensitivity and is therefore designated as the gold standard for HCP detection by regulatory agencies.

 **3. MATERIALS (Note: Storage at 2-8℃)**

 Appendix 1: example OF Standard Curve