BioSystem Development’s Assay MAP MAb Titer is the company’s first application-specific product. It is primarily used for optimizing monoclonal antibody cell culture during process development. The MAb Titer is a miniature spin column in a cartridge format, containing 192 packed beds. First, the cartridge is wetted with 5 µL of protein A resin, an antibody affinity ligand, and five to a few hundred microns of cell culture media, which can be introduced manually or with a liquid handler. The entire cartridge, like a spin column, is placed into a centrifuge to separate and capture the IgG antibodies. “The major difference between the MAb Titer assay and a spin column is that spin columns and extraction columns, in general, are not quantitative,” explained Scott Fulton, CEO of BioSystem Development. “The ones that are, are around 10 times larger in volume.” After the cartridge is run through the centrifuge, the nonbinding materials in the cartridge are washed out into a 96-well plate microtiter plate where antibody concentration is read on a plate reader, a process not possible with larger spin columns.

The MAb Titer’s main competition for antibody quantitation during cell culture process development is protein A HPLC. Because the MAb Titer uses the same protein A resin and buffers as those found in protein A HPLC columns, it also has the same chemistry. “We went to great lengths to make sure that [drug development companies] don’t have to change anything.” According to Mr. Fulton, the MAb titer can run a 192-sample cartridge in 20 minutes, while HPLC can run one sample in 10 minutes.