Archive for June, 2012

Causes of In-Vitro Hemolysis

Posted 19 Jun 2012 — by admin
Category Clinical Chemistry, Laboratory Procedures

The causes of in-vitro hemolysis are many resulting from the specimen collection, to specimen processing and to specimen storage.

What is in vitro hemolysis?

In vitro hemolysis is the lysis or destruction of red blood cells (RBC) outside the body. The RBCs could either swell or shrink, destroying the RBC.

Here are some causes of hemolysis:

  • Using a smaller gauge than the standard. Ideal gauge of needle for venipuncture is usually 20-22. A gauge 25 needle is one significant cause of hemolysis, especially if blood specimens are handled roughly.
  • Squirting the blood directly into the specimen container.
  • Squirting the blood without removing the needle.
  • Using wet equipment, like wet syringes and wet test tubes.
  • Shaking the specimen vigorously.
  • Freezing the blood immediately after collection.

Hemolyzed serum should not be used in laboratory tests because it would yield unreliable results.

What are the Differences between Serum and Plasma?

Posted 19 Jun 2012 — by admin
Category Clinical Chemistry, Laboratory Procedures

Serum and plasma are types of blood specimens that are utilized in testing for the concentrations of substances in the blood. They are supernatant fluids obtained after centrifugation of clotted blood and noncoagulated blood, respectively.

Here are some differences between serum and plasma:

Category Serum Plasma
color light yellow lighter
transparency clearer than plasma less clear than serum
Serum protein present albumin, globulin albumin, globulin,  fibrinogen
anticoagulant absent present

Why is serum generally the most preferred blood specimen for clinical chemistry tests?

Serum is the preferred specimen because they have fewer proteins, which are considered as interfering substances for some tests.