Concurrent separation of plasma and of viable blood cells

Fractions of viable, morphologically intact erythrocytes, leukocytes, and platelets were isolated concurrently with plasma from single samples of human blood. The four compartments were separated immediately after the collection of blood as well as at different times up to 120 minutes after the drawing. In addition, the cellular separation was applied at various intervals after the initial removal of plasma. All steps of the procedure were carried out at room temperature using simple laboratory equipment. The cross-contamination of the cellular fractions, obtained in yields ranging from 33 per cent to 69 percent was less than 5 per cent. More than 96 per cent of the isolated cells excluded trypan blue and retained lactate dehydrogenase. Regardless of the conditions of separation, the cellular contents of potassium in erythrocytes, leukocytes, and platelets were constant, averaging 270, 387, and 209 nEq. per milligram of protein, respectively. The isolated cells also maintained high ratios of cellular K+/Na+, except after their delayed isolation following the initial separation of plasma. Under the latter conditions, the cells were characterized by a gain in cellular sodium despite an unchanged content of potassium. The separation procedure was routinely applied to 5 to 10 ml. samples of blood, obtained from randomly selected volunteer subjects.