A rapid screening method to monitor expression of various recombinant proteins from prokaryotic and eukaryotic expression systems using MALDI-TOF mass spectrometry

Rapid methods using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry to monitor recombinant protein expression from various prokaryotic and eukaryotic cell culture systems were devised. Intracellular as well as secreted proteins from both induced and constitutive expression systems were measured and monitored from whole cells and growth media, thus providing an alternative to time-consuming traditional methods for screening and monitoring of protein expression. The methods described here involve minimal processing of samples and are therefore relevant to high-throughput screening applications.