Application Note: Quantitation of intact therapeutic protein in plasma matrix by LC/MS

A complete workflow to quantify intact therapeutic proteins in plasma matrix has been developed, covering three critical components in preclinical sample analysis: target protein enrichment/purification, LC/MS data acquisition and quantitative data analysis.

Trastuzumab in rat plasma was enriched/purified with one-hour immuno-capture workflow, to remove background matrix. The enriched/purified intact trastuzumab samples were analysed by high-flow LC/MS in SCIEX X500B QTOF system. A Novel data processing strategy with automated data reconstruction in PeakView^® software was utalised to filter out interference from residual matrix proteins. Quantitation of trastuzumab in rat plasma at intact protein level was achieved with a linear dynamic range of 100 ng/mL to 50,000 ng/mL and a limit of detection of 50ng/mL in 50 µL of rat plasma.