1. If a specific procedure is described for a certain suspension culture this procedure has to be followed for routine transfer of the suspension to fresh medium.

2. For all other suspensions the transfer to fresh medium is done as follows:

2.1. The Erlenmeyer flasks containing the cell suspensions to be transferred are taken from the gyratory shaker and transported into the transfer room.

2.2. The flasks to be transferred are placed under the clean bench.

2.3. The aluminium foil closures of the flask containing the suspension and of the flasks containing the fresh medium are carefully removed and the bottlenecks are carefully heated up in a flame. The opening of the flasks are loosely covered by the aluminium foil closures.

2.4. The suspension cells are allowed to settle down.

2.5. The bulk amount of the medium is carefully poured off into a waste bottle.

2.6. The cells and the remaining medium are mixed to achieve again a homogeneous suspension and poured into the flasks containing fresh medium. Normally the remaining volume of the old suspension is split into two parts to inoculate two new suspension flasks.

2.7. The bottlenecks of the freshly inoculated flasks are heated up in a flame and closed with the aluminium foils again. Since the bottlenecks may still be hot a leather glove should be used to protect the skin.

2.8. On the freshly inoculated suspension culture flasks the name of the cell line and the date of inoculation should be noted.

2.9. The flasks are transported back to the culture room and placed on a gyratory shaker.