A cover effective to releasably seal a multiwell container, such as a microtitration plate, is disclosed. The cover contains a pad, fashioned from a flexible polymer sheet, and a plurality of resiliently compressible ridges formed on the sheet. The ridges are deformable, such that application of pressure...http://www.google.es/patents/US5604130?utm_source=gb-gplus-sharePatente US5604130 - Releasable multiwell plate cover
