A method for reducing the pressure in and then collecting medium samples in containers such as test tubes sealed by a resilient stopper at substantially atmospheric pressure, comprising piercing the stopper at or shortly before the time of collection of a medium sample by a first cannula, connected at...http://www.google.com/patents/US4063460?utm_source=gb-gplus-sharePatent US4063460 - Method for evacuating and then collecting medium samples in containers sealed by a resilient stopper at substantially atmospheric pressure
