Peter van Mourik

86 Chapter 4 1. The colon biopsies should be stored on ice or at 4°C (fridge) in properly labelled 50 mL polypropylene conical tubes containing 30 mL of PBS0. Make sure the tissue is NOT frozen. Note: If the biopsies are transported over long distances or over a long duration (>8 hs) before the crypt isolation procedure can be initiated, the biopsies should be stored in Ad-DF+++ with additional gentamicin (50 µg/mL) and vancomycin (50 µg/ mL) at 4°C. 2. Make sure the 50 mL conical tube containing the colon biopsy in the storage medium is tightly closed and properly labelled. The date of the biopsy collection should be written on the tube (preferably on a sticker). 3. During the biopsy transport, the temperature needs to be 4°C. Please use cold gel or ice packs during the shipment. CRITICAL: Wet ice should not be used for the shipment, since thawing ice might damage the labelling of the tubes.