To characterize the two products that have been successfully used for an antibody-producing cell culture process, principal
component analysis was used. The data from a total of 17 lots—12 lots from vendor A (called product A) and 5 lots from vendor
B (called product B)—were used for this analysis. The raw material type (product A or product B) was treated as a qualitative
X variable and all the analytical data was used as continuous X data. The first principal component was able to explain 61% of variation in X data (R2X = 0.61), and this component was able to predict 54% of the variation in data (Q2 = 0.54). The addition of a second principal component resulted in the cumulative goodness of fit (R2X) and predictability (Q2) values of 0.77 and 0.50. Because the addition of second principal component decreased the model predictability to 0.50,
this component was ignored and only the first component was used for analysis. The principal component analysis showed that
the two products were distinct and belonged to different clusters in M-space. The correlation structure was analyzed using
the loading plot. Product B, n-6 fatty acids, [n-6]:[n-3] ratio, and free fatty acids clustered together and appeared diagonally
opposite to the cluster containing LDL, LDL:HDL, VLDL, VLDL:HDL, and PC. These results suggested that compared to product
A, product B was richer in n-6 fatty acids and free fatty acids and had a higher [n-6]:[n-3] ratio. On the contrary, product
A was richer in n-3 fatty acids and phosphatidylcholine. Product A also had a higher content of LDL and VLDL and had higher
LDL:HDL and VLDL:HDL ratios compared to product B. It is likely that the dissimilarities between products A and B are due
to the differences in starting sera that in turn may be related to the feeding practices of different herds used for serum
production.
Anurag S. Rathore, PhD, is a consultant, Biotech CMC Issues, and a member of the faculty in the department of chemical engineering at the Indian Institute of Technology. Rathore is also a member of BioPharm International's Editorial Advisory Board.
Articles by Anurag S. Rathore, PhD
