Identification of monoclonal antibodies based on Drop-Coating Deposition Raman imaging (DCDR) combined with Multivariate Curve Resolution Alternating Least Square (MCR-ALS) analysis

Glycosylation is considered as a critical quality attribute of therapeutic proteins taking
into it affects their stability, bioactivity, and safety. Hence, the development of
analytical methods able to characterize the composition and structure of glycoproteins
is crucial. Currently, existing methods are time-consuming, expensive, and require
significant sample preparation, which can alter the robustness of the analyses [1]. In
this context, we developed a fast, direct, and simple Drop-Coating Deposition Raman
imaging (DCDR) method combined with Multivariate Curve Resolution Alternating
Least Square (MCR-ALS) analysis to identify the monoclonal antibodies (mAbs).
In the present study, DCDR imaging combined with MCR-ALS analysis proved
efficient in the identification of 16 glycoproteins in their pharmaceutical formulation.
The process of drying the drop allowed the separation of solutes by forming “coffee
ring” [2]. It was demonstrated that, while the buffer salts and excipients dried around
the center of the drop, the mAbs stayed outward on the edge and concentrated on the
ring of the drop.