Figure 5. (a ) Raman spectra for different antibody types; (b ) plot of Qr versus Tr2 for a principal component analysis (PCA) model developed using the spectra in (a) 95% confidence level. Decision criterion: Qr ≤ 1.5, pass; Qr > 1.5, fail.
4. Conclusion
The combination of Raman spectroscopy and PCA achieved the level of specificity needed to differentiate the activity of solution-based protein products. Handheld devices present the advantage of providing quick results, with initial screening possibly performed on the field by the end-user in a single step in less than 5 min, rather than having to send the samples to the laboratory. Furthermore, other CQAs, such as appearance, purity of SEC-HPLC, charge heterogeneity of CEX-HPLC, and bioassay, verified the results of the mAb identification by Raman spectroscopy. The results of the mAb identification by Raman spectroscopy changed in response to the other CQAs. Therefore, mAb identification by Raman spectroscopy based on the PCA of multivariate algorithms can be used as a novel and reliable tool for mAb identification. Different types of antibody identification can be performed by Raman. A nondestructive measurement technique should always be preferred.