A Platform Approach for the Purification of Domain Antibodies (Dabs)

A three-step purification process for a Dab successfully developed and verified. The step yield ranged between 86% and 99%, giving a total process yield of approximately 81%. The ECP in the start sample was more than 200 000 ppm whereas the final sample contained only 5.5 ppm. The endotoxin content in the feed was approximately 2 million endotoxin units/mg of protein and the final sample was below the limit of quantification. Protein L leakage was undetectable in all samples. This platform approach, based on a capture step with Capto L, enables increased efficiency and productivity in developing therapeutics based on Dabs.