The most common technique for separating leucocytes is to mix blood with a compound which aggregates the erythrocytes, thereby increasing their sedimentation rate. 

The sedimentation of leucocytes is only slightly affected and can be collected from the upper part of the tube when the erythrocytes have settled. Using a mixture of sodium metrizoate and polysaccharide, Bøyum (1968) developed a one-step centrifugal technique for isolation of lymphocytes. 

Thorsby and Bratlie (1970) used this technique with only slight modifications in the preparation of pure lymphocyte suspension for cytotoxicity tests and lymphocyte cultures. As emphasized also by other authors, Harris and Ukayiofo (1969), Ting and Morris (1971) this is a reliable, simple and quick method suitable for the preparation of lymphocyte preparations from cadaver blood, and from anti-coagulated blood stored at room temperature for up to 6 hours.

STABILITY AND STORAGE Lymphoprep™ is stable for 3 years provided the solution is kept sterile and protected from light. Prolonged exposure to direct sunlight leads to release of iodine from the sodium diatrizoate molecule. This effect is negligible when working with this solution on a day to day basis. Lymphoprep™ should be stored at room temperature.