ELISA Kit for the Quantitative Measurement of HEK 293 HCP Residues in Cell Culture Supernatants, Protein Purification Process, and End-Product

**1. APPLICATION**

The kit is intended for the quantitative determination of residual host cell protein in protein therapeutics produced by HEK 293 expression systems.

**2. BACKGROUND**

Human Embryonic Kidney 293 Cells, commonly known as HEK 293, are widely utilized for the expression of therapeutic proteins. The process of expressing target proteins involves concomitant apoptosis, which releases up to a thousand host proteins into the cell culture medium after cell breakdown. 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 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