Lectin-based glycosylation profiling of IgG via plasmonic fluorescence enhancement

 

 

Derek S. Smith and Michael J. Tarlov

 

Process Sensing Group, Process Measurements Division, CSTL, NIST

 

 

In the production of therapeutic glycoproteins, detailed characterization of the different glycoforms of the protein is essential due to the impact that glycosylation has on product efficacy and safety. Conventional glycoanalytical methods are laborious, time-consuming, and require extensive expertise in sample preparation and analysis rendering such methodologies impractical for high-throughput glycosylation screening or near real-time process monitoring. Here, we describe a surface-based, plasmonic-enhanced fluoroimmunoassay that eliminates separation steps while still allowing high sensitivity detection of biomolecular interactions. The assay is performed on glass substrates coated with silver island films that generate metal-enhanced fluorescence allowing the detection of bound probes in the presence of unbound probes. Lectins (labeled or used as a capturing agent) are employed to interrogate the glycosylation of recombinant IgG from cell culture. It is possible through optimization of the procedures that real-time glycosylation profiling during cell culture is attainable.