Related Experiment Video For biological activity
Updated: Mar 23, 2026

A "Dual-Addition" Calcium Fluorescence Assay for the High-Throughput Screening of Recombinant G Protein-Coupled Receptors
Published on: December 2, 2022
Quality-control method for the determination of biological activity of engineered calcineurin subunit B
Xinchang Shi1, Huan Yang2, Li Xu1
1Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, Beijing, 100050, China.
Abstract:
The aim of this study was to establish a quality-control method for calcineurin subunit B (CNB) biological activity determinations. CNB enhances the p-nitrophenylphosphate (pNPP) dephosphorylating activity of calcineurin subunit A Δ316 mutant (CNAΔ316). A series of CNB concentrations were fitted to a four-parameter equation to calculate the corresponding pNPP maximum dephosphorylation rates. Values were calculated based on biological activity references using a parallel line method. The method was then validated for accuracy, precision, linearity, linear range, sensitivity, specificity, and robustness. The recovery results were greater than 98%. Intra-plate precision was 6.7%, with inter-plate precision of 10.8%. The coefficient of determination was greater than 0.98. The linear range was 0.05-50 μg mL(-1), with sensitivity of 50 μg mL(-1). Tested cytokines did not induce CNAΔ316 dephosphorylation of pNPP. The chosen CNAΔ316 concentration range did not affect activity determinations.

