To Maintain COS-7 Cells:

Medium = RPMI (Gibco; from Tissue Culture Center)

+ 10% HI-FCS

+ Pen/Strep 1ml per 100ml (Final = 100 u/ml Pen/100 ug/ml Strep)

+ L Gln (1ml per 100ml)

Re-feed every 3-4 days, and passage every 7-10 days.

For passaging cells:

· Aspirate medium

· Trypsinize – add 1ml trypsin/EDTA then aspirate and put at 37 deg for 3-5 minutes

· Add 5 ml fresh medium and add 0.3 ml of this into 3 ml of fresh medium.

(It is best to use pre-warmed medim, but not absolutely critical)

Frozen Stocks:

· Confluent 75 cm² flask

· Trypsinize as usual, then add 10 ml fresh medium containing10% HI-FCS and 5% DMSO (Use fresh/sterile bottle of DMSO that is reserved for tissue culture work.)

· Freeze 0.5 ml aliquots in o-ring tubes at –80 deg for 1-3 days, then transfer to liquid N₂.