A Vacutainer blood collection tube is a sterile glass or plastic tube with a closure that is evacuated to create a vacuum inside the tube facilitating the draw of a predetermined volume of liquid. Tubes are available with or without a safety-engineered closure, with a variety of labeling options and closure colors as well as a range of draw volumes.

Vacutainer tubes may contain additives e.g. anticoagulants designed to stabilize and preserve the specimen prior to analytical testing. When collecting venous blood, the ratio of blood to anticoagulant is critical to the quality of the collected blood. To be specific, if the volume of anticoagulant is relatively insufficient, the clot may occur to the blood and block the testing instrument. On the other hand, if the volume of the blood is relatively insufficient, the testing accuracy may be compromised, too. Since the blood is forced into the tube by the pressure difference between the blood volume and the vacuum in the tube, it is important to control the vacuum degree of the vacutainer blood collection tube.

Figure 1. Vacutainer Blood Collection Tubes

In addition to the ambient pressure, temperature and the seal performance of vacutainer tube, the gas barrier property of the vacutainer tube is another factor that may influence its vacuum degree. It can be easily understood that the vacuum degree will be reduced if there is much air permeating through into the vacutainer tube, especially when the vacutainer tube is stored for a long period before use. Therefore, it is necessary to test the gas permeability of the vacutainer tube.

Hereinafter we take plastic vacutainer blood collection tube as an example to elaborate on how to test the gas permeability of the vacutainer tube. The testing instrument used to measure the gas permeability is Labthink’s G2/130 Container Gas Permeability Tester, which adopts differential pressure method where the pre-conditioned hollow container is mounted in the gas diffusion cell as to form a sealed barrier. The inner and outer chambers of container are evacuated firstly, followed by the evacuation of the entire cell. A flow of test gas is thereafter introduced into the evacuated outer chamber and a constant pressure difference is generated between two chambers. The gas permeates through the specimen from higher pressure side into the lower side. The gas permeability and other barrier properties of the specimen can be obtained by monitoring the pressure difference of inner chamber.

The tests shall be performed according to the following test procedures.

(1)    Paste the specimen on the sample support with Aradite Rapid Transparent Adhesive. Then fix the sealing cover.

Figure 2. Mount the Specimen

(2)    Set specimen name, test parameters and other necessary information.

(3)    Click Test and turn on the vacuum pump to start the test.

(4)    The instrument will display the test results automatically after tests.

For more details about G2/130 Container Gas Permeability Tester, please visit www.labthink.com

About Labthink Instruments Co., Ltd:

Labthink Instruments Co., Ltd is one leading supplier of packaging testing instruments, which is headquartered in Jinan, China and operated in Boston, U.S.A.