Since vacutainer tubes contain the pre-measured vacuum and pre-measured additives, each tube must be completely filled to the “specified filling volume.” When performed, it allows the technologist to microscopically view the actual appearance of red and white blood cells. Vacutainer tubes are covered with a color-coded plastic cap that shows which additives the tube contains. This may result in changes in the concentration of certain analytes.
The specified anticoagulant or preservative must be used for the ordered test.
Which blood tube is used for CBC?
When using a benchtop centrifuge, use a balancer tube of the same type that contains an equivalent volume of water. Since additives are not interchangeable, it is necessary to consult the sample requirements section of the individual test descriptions to determine the appropriate collection requirements for the ordered test. Blood cells are suspended in plasma, which consists of water and dissolved materials, including hormones, antibodies, and enzymes that are transported to tissues, as well as cellular waste products that are transported to the lungs and kidneys. Hemolysis can be caused by rough handling of a blood sample, by allowing the tourniquet to run too long (causing blood congestion), or by squeezing the fingertip too much during capillary collection, dilution, exposure to contaminants, extreme temperatures, or pathological conditions.
Which vacutainer tubes for which tests?
To repeat once again: The color of the tube cap indicates the type of additive the tube contains for a common laboratory test. Prior to the invention of modern blood collection tubes known today, blood collection systems and devices were difficult to use and were generally inaccurate. This combination creates a stronger, stronger tube that is more resistant to breakage and chemical damage. For a clearer explanation of these clinical test tubes, here is a general overview of which Vacutainer tubes should be used for which tests based on the shade of the cap.
Most of these collection tubes, which contain an additive, either specifically prevent blood clotting, also known as an anticoagulant, or accelerate blood clotting.
Can you run a CBC on a green top?
Heparin (green top tube) is not recommended as an anticoagulant for cell counts as the cells clump together into heparin, which invalidates the count.
What is the difference between red and purple vacutainer tubes?
Vacutainer blood collection tubes are sterile glass tubes with rubber stoppers that draw a preset volume of liquid or blood. This is your basic hematology tube (by which I mean identifying and counting blood cells, blood type, etc.). Don’t confuse serum with plasma, as both are the liquid, cell-free portion of blood that can be obtained through centrifugation. The main difference is that serum is the product of blood that was allowed to coagulate, whereas in a plasma sample, the dense cells are simply spun downwards. The Vacutainer needle is double-ended, with one side covered with a thin rubber coating for safety reasons and the other side for insertion into the vein.