An interlaboratory capillary zone electrophoresis-UV study of various monoclonal antibodies, instruments, and ε-aminocaproic acid lots.

Capillary zone electrophoresis ultraviolet (CZE-UV) has become increasingly popular for the charge heterogeneity determination of mAbs, and vaccines. The ε-aminocaproic acid (eACA) CZE-UV method has been used as a rapid platform method. However, in the past years, several issues have been observed, e.g., loss in electrophoretic resolution or baseline drifts. Evaluating the role of eACA on the reported issues, various laboratories were requested to provide their routinely used eACA CZE-UV methods, and BGE compositions. While every laboratory claimed to use the He et al. eACA CZE-UV method, most methods actually deviate from He's. Subsequently, a detailed interlaboratory study was designed wherein two commercially available mAbs (Waters' Mass Check Standard mAb (pI 7) and NISTmAb (pI 9)) were provided to each laboratory, along with two detailed eACA CZE-UV protocols for a short-end, high-speed, and a long-end, high-resolution method. Ten laboratories participated each using their own instruments, and commodities, showing excellence method performance (RSDs of percent time-corrected main peak areas from 0.2% to 1.9%, and RSDs of migration times from 0.7% to 1.8% (n = 50 per laboratory), analysis times in some cases as short as 2.5 min). This study clarified that eACA is not the main reason for the above-mentioned variations. This article is protected by copyright. All rights reserved.