Preparation of the microcarrier

1) Swell the dry beads made of cross-linked dextran, polyacrylamide or gelatin in PBS-A or Hepes buffered saline as described by the manufacturer. The cross-linked dextran beads require 2-3 h to swell at room temperature. Avoid stirring with a simple bar magnet as this may grind the beads. Addition of non-ionic detergent (e.g. Tween 80) to 0.1% may help initial wetting of the microcarrier. 

2) Wash the beads by decantation and resuspend in the swelling buffer. Glass and plastic beads can be suspended in water. 

3) Dispense into appropriate bottles at about 1 g per bottle for the beads that swell or 10 g per bottle for the glass and plastic beads. 

5) Before use, decant the supernatant and soak the beads in 2-3 volumes of warm culture medium for 30 min. 

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