EVACUATED BLOOD COLLECTING DEVICE

摘要

An evacuated blood collecting device for collecting a blood sample of predetermined volume comprises: a cylindrical member having one open end and one closed end; a puncturable stopper member closing tightly the open end of the cylindrical member so as to seal the space within said cylindrical member; and a gas sealed in the space within the cylindrical member. The cylindrical member and the stopper member are made of materials having a characteristic such that the permeation coefficient of the gas sealed inside the space to at least one of the cylindrical member and stopper member is higher than that of the gas around the outside of the blood collecting device, whereby the interior of the space is retained under reduced pressure relative to the gas around the outside of the blood collecting device in proportion to the blood sampling volume.