In a sample of peripheral whole blood, less than 1% of the cells are white blood cells (WBCs) and platelets. When researchers put the sample through a centrifuge, a machine that spins the blood, those WBCs and platelets combine to form their layer suspended between the red blood cells (RBCs) and supernatant plasma. This thin layer is called a buffy coat because of its color (yellowish to brownish). A "Buffy Coat", also known as leukocyte concentrate, is a byproduct in the manufacturing of red blood cell and platelet concentrate from a whole blood donation.
Facts about Buffy Coat
- Ideal for the isolation of cells.
- Byproduct in the processing of blood.
- Leukocyte reduction helps to prevent complications of blood transfusion.
- The preparation is carried out physically without the use of polymer solutions.
- Leukocytes are 10 to 20-fold more concentrated than in whole blood.
Buffy Coat Preparation
Two ways are suitable for the preparation of a buffy coat. On the one hand, the whole blood donation is centrifuged to separate the whole blood into red cells, plasma, and buffy coats. The second possibility is to filter the blood and hold back the leukocytes. It is important to remember that a whole blood sample could contain pathogens, so these samples must be handled with standard precautions as if capable of transmitting infectious diseases.
First, the correct type of tube for the blood will need to be determined. The blood in an EDTA tube needs to be processed within 2 hours and a STRECK tube needs 24 hours. Additionally, the sample could contain diseases, contaminants, or infections. For this reason, proper safety precautions must be taken when preparing for buffy coat extraction.
The sample is placed in the centrifuge machine, ensuring that the sample is balanced and properly secured. Typically, the spinning process lasts approximately 10 minutes.
Using a pipette, the now concentrated leukocyte layer (aka the buffy coat) is extracted from the top of the centrifuged sample. The amount of buffy coat collected will be approximately 20 percent of the original whole blood sample.
Creative Bioarray Relevant Recommendations
- Creative Bioarray provides three types of Buffy Coat Isolation Kit, including the Human HLA Buffy Coat CD56 Isolation Kit, Human CD14 Cell Isolation Kit (Buffy Coat), and Human CD56 Cell Isolation Kit (Buffy Coat). These kits are fast, efficient, and easy to use. No column is required for use and they have a high purity of 99% and high recovery.
Applications of Buffy Coat
- Buffy coats are important for DNA isolation from blood samples. Especially in the case of the mammalian blood sample with non-nucleated RBCs, DNA extraction is performed from white blood cells as leukocytes are about ten times more concentrated sources of nucleated cells.
- The use of a buffy coat reduces donor variability as donor-specific soluble serum factors are eliminated with the rest of the discard.
- The platelet-rich buffy coats have become an alternative source for the platelet concentration method as the buffy coat preparation causes less platelet activation and damage.
- A quantitative buffy coat is a standard laboratory test to detect infection with malaria or other blood parasites like trypanosomes, Leishmania, and Histoplasma.
- Buffy coat preparation is a cheaper method of blood cell separation, and it is also the ideal method to meet the emergency requirement for platelets.