Diminishment of GSH leads to formation of dense cells. Percent of high density cells (% HDSS) formed were calculated and plotted after density separation via Percoll gradients of SS RBCs, which underwent incubation at 4°C of low density (45% Percoll layer) sickle cells without (−□−□−) or with (−▪−▪−) 1 mmol/L CDNB. Mol concentrations of GSH were determined in the same RBCs in the absence (−○−○−) and in the presence (−•−•−) of 1 mmol/L CDNB. Data is presented as mean ± standard error of four independent experiments. Values for GSH and HDSS were statistically significant (P < .05) at 1 hour, 12 hours, and 24 hours when comparing ± CDNB samples.