Abstract: The present invention provides for a biological specimen collecting system for holding a biological specimen in a long term sustained sealed environment. The biological specimen collecting system includes a container for holding the biological specimen and a sealing closure cap. The container is of circular section and has generally vertical sidewalls, the sidewalls at the top terminating in an inwardly sloping sealing surface. The container has a first thread on an exterior surface thereof, the first thread being located below the sealing surface. The sealing closure cap has a peripheral groove to receive the container rim, the peripheral groove being defined by inner and outer walls and a top. The outer wall of the groove is provided with a second thread complementary to the first thread on the container for engagement therewith.