Studies on Rosette Formation of Human Peripheral Lymphocytes with Sheep Red Blood Cells

Abstract

Lymphocytes were isolated from venous blood of patients or normal individuals by Conray-Ficoll density gradient. Zero point one ml of lymphocyte suspension adjusted to the concentration of 5×10^6 cells/ml was mixed with the equal volume of 0.5% sheep erythrocytes and incubated for 15 minutes at 37℃ and then for at 4℃ or O℃ under various conditions and the rate of rosette formation was compared among these conditions. Lymphocytes binding more than 3 sheep erythrocytes were considered to be positive. By method I, in which Eagle's MEM (minimum-essential medium) with 10% fetal calf serum was used as medium, the percentage of sheep red blood cell-rosette forming cells was 40.1±5.8% (mean ± s.d.) in 25 healthy individuals. By method II in which Hanks' BSS was used, it was 56.3±7.2% in 45 healthy individuals.