We have happily made a transition last year from using Invitrogen's SFM medium and cellfectin to Insect-Xpress (Lonza) and polyethyleneimine for transfection. We are moving several protein targets to large-scale cultures and would consider cost-cutting alternatives. For example, Invitrogen and Thermo Sci both offer media in powder form at an attractive price. Has anyone made a systematic comparison of these media? Any particular recommendations regarding powder media?
Last I checked, no manufacturer offered serum-free powedered medium. Fetal calf serum is very expensive - once you count in its cost, the overall price of the media becomes comparable. If your protein is secreted, serum-containing media are not even a realistic choice. If it is intracellular, buying dry medium and adding FBS work well: is a lot more hassle, is about 20% cheaper, and usually gives slightly higher titers and expression levels. Of all the common media we compared, TNM-FH works best for us with Sf9 cells. Switching to dry medium also means some initial investment: bottles, filtration equipment and filters. So it all pays off only of you need large scale cultures long-term. If you are aware of a dry serum-free insect cells medium, please let me know - I'd love to try it. Dima
