Autoclaving and use of sandwich covers: 1. Wrap the sandwich cover (on top of a polypropylene MTP, or without an MTP in case gamma-irradiated polystyrene MTPs are to be used) in aluminium foil (alternative: use a sterilization bag). 2. Autoclave for 20-30 minutes at 120 ºC, preferably followed by a dry cycle. 3. Remove the aluminium foil. 4. If the autoclave used had no dry cycle option, dry the sandwich cover (with or without the MTP) in an oven set at ~ 100-110 ºC for 1 hour, in order to dry the filter layers . 5. Place the sandwich cover (with or without the MTP) in a laminar flow cabinet. 6. Fill each well of the sterile MTP (using e.g. a multipipette or a filling station) with an appropriate sterile liquid growth medium (for adviced volumes, see the pages on the hydrodynamics and oxygen transfer rates). 7. Inoculate the wells of the MTP, either individually, or using a colony picker, or a replicator (see our webpage on the “use of the replicator”). 8. Put the sandwich cover on top of the MTP. 9. Position the sandwich cover + MTP into one of our clamp systems (attached onto an orbital shaking platform), as described on the page “use of clamp systems” .
Cleaning and maintenance of the sandwich covers - after use, the spongy silicone layer can be cleaned using a tissue and a water- ethanol mixture . - do not disassemble sandwich cover unless absolutely necessary. - the microfiber filter (blue) and the ePTFE filters (green) can be used for at least 20-50 times: replace if too dirty. Replacement filters can be obtained in packages of 20. - the spongy silicone layers can be re-used for hundreds of times, provided the sandwich covers are not compressed longer than about 10 days (in the latter case, the silicone layer may not fully regain its original shape).
Use of sandwich covers