Extracting Serum from Whole Blood Sample

In this video, we will learn how to properly extract serum from a whole blood sample.

Obtaining the Blood Sample

• Use a glass test tube or a test tube with clot activators to collect the blood sample.

• Ensure that the patient sample is labeled according to hospital protocol, including the patient's name, hospital identification number, and date of birth.

Allowing Blood Clotting

• Allow the blood to fully clot for 15 to 30 minutes.

• Check if the blood has fully clotted by gently tilting the tube. Avoid vigorous shaking as it may cause hemolysis.

Centrifugation

• Centrifuge the clotted tubes at 1000 to 2000 g's for 10 minutes.

• After centrifugation, gently remove the tubes without disturbing the settled cell components.

Removing Gel-like Substance

• Sometimes, a gel-like substance may be present in the tube after centrifugation. This prevents easy access to serum.

• Run a toothpick along the inner walls of the tube to remove the gel rim.

• Re-centrifuge the tube for one to two minutes.

Transferring Serum

• Transfer the patient's serum into a new clean labeled test tube before testing.

• Normal serum appears pale yellow and clear.

Rejected Samples

• Lipemic serum: Turbid appearance due to increased lipids in the blood (triglycerides).

• Hemolyzed sample: Result of intravascular hemolysis or improper handling during collection and processing.

Ensuring No Contamination

• Re-centrifuge the tube for another minute to ensure no contamination from cellular blood elements.

• Carefully transfer only serum into a new test tube without disturbing the blood pellet.

Storage and Use of Serum

• Serum samples can be used immediately or stored in the refrigerator for two to three days until use.

The timestamps provided are approximate and may not match the exact timing in the video.