Microchip assays for screening monoclonal antibody product quality.
Microchip CE-SDS was evaluated as a high-throughput alternative to conventional CE-SDS for monitoring monoclonal antibody protein quality. A commercial instrument (LabChip) 90) was used to separate dodecyl sulfate coated proteins through a sieving polymer based on the proteins' sizes. Under reducing conditions, the microchip CE-SDS separation was similar to that of conventional CE-SDS, providing reasonable resolution of the non-glycosylated and the glycosylated heavy chains. The fluorescence detection on LabChip 90 using non-covalent fluorescent labeling method was about as sensitive as the 220 nm UV detection used in a conventional CE instrument. A simple glycan typing assay was developed for the reducing microchip CE-SDS format. Antibodies, either pure or in crude cell culture media are treated with Endoglycosidase H, which specifically cleaves the hybrid and high mannose type glycans. A heavy chain migration shift on reducing CE-SDS resulting from the loss of glycan is used to measure the level of high mannose/hybrid type glycans as a percentage of the total glycans. Microchip CE-SDS, under both non-reducing and reducing conditions, can be used in a variety of antibody product screening assays. The microchip analyses provide sufficient resolution and sensitivity for this purpose but on a time scale approximately 70 times faster (41 s versus 50 min per sample) than conventional CE separation under typical operational conditions.
Chen
Xiaoyu
X
Analytical and Formulation Sciences, Amgen Inc, Thousand Oaks, CA 91320, USA.
Tang
Kaiyan
K
Lee
Maximilian
M
Flynn
Gregory C
GC
D000911:Antibodies, Monoclonal / Q000032:analysis*; D046209:Electrophoresis, Microchip / Q000295:instrumentation / Q000379:methods*; D011786:Quality Control; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry
D000911:Antibodies, Monoclonal; D012967:Sodium Dodecyl Sulfate; C028913:dodecyl sulfate