The effect of varying SRBC/lymphocyte ratio on T cell rosette formation.

To determine the effect of varying the SRBC/lymphocyte ratio on rosette formation, rosettes were formed at SRBC/lymphocyte ratios ranging from 10 to 200. To assess the significance of the time of incubation, duplicate samples were mixed at various SRBC to lymphocyte ratios and the percentage of rosette-forming lymphocytes was determined immediately or after an 1-hour incubation at 4 degrees C. The results of five experiments revealed the highly statistically significant difference between the percentage of rosette-forming cells in tests performed with (higher number of RFC) and without (lower number of RFC) incubation, in all SRBC/lymphocyte ratios. On the other hand, ratio of SRBC to lymphocytes influenced significantly the results obtained in both types of tests, this effect was more pronounced in test performed with 1-hour incubation. Optimal SRBC/lymphocyte ratios for both tests were 100:1 (31% RFC without incubation and 53.4% of RFC after 1-hour incubation.