MSP expression is generally a day long affair, but otherwise follows a fairly standard expression protocol using BL21DE3 or C41 cells.
Plasmids
Expression must be done in one day as MSPs degrade over time in E. coli. Thus overnight, low temperature inductions result in trifling amounts of poorly formed protein. Inductions performed below target OD will also result in poor amounts of misfolded protein. Starters should be done a day before, and each flask of 1L TB should receive 16-25mL of starter culture. Prewarming the incubator and media a day before large scale expression can speed things along. During the day, generally expect low ODs for the first few hours. Be patient while the OD creeps up relatively slowly before large increases. For example, flasks of TB (which have not bee prewarmed) inoculated with 18mL of starter culture take ~ 5 to 6 hours to reach an OD of 0.6. Pre-warmed flasks will reach an OD of 0.9 after 5-6 hours. As with all bacterial expressions, high quality cells (i.e. OneShot or freshly made, competent stocks) only helps with final protein yield and quality.