Table 1.
Host-cell proteins (HCPs) identified in six PTG1 preparations and their corresponding concentrations (ppm, expressed in ng HCP/mg total protein) The protein concentrations were calculated using top three best responding peptides in ESI-MS [38]. All samples were purified on a ProSep-vA column (EMD Millipore). Samples A1/A2 and B1/B2 were biological replicates, grown in a DG-44 CHO cell line. Samples C/D were expressed in a CHO-S cell line. The MRM assays were developed for three proteins highlighted in bold.