5.1 Leukocytes (Buffy Coat) Isolation

Leukocytes, more commonly known as white blood cells, are a type of peripheral blood mononuclear cell (PBMC), which means that unlike red blood cells PBMCs have a nucleus. While they make up less than 1% of the blood by volume, they will yield the majority of the DNA contained in blood samples:

It its therefore advised to isolate the leukocytes before proceeding with DNA isolation for better results. Many protocols already incorporate this step, but for some circumstances it may be useful to process the entire blood sample this way before proceeding.