Use of Histopaque for isolating mononuclear cells from rabbit blood

This paper describes the use of Histopaque (Hp) density gradient medium and its advantage for separating mononuclear cells (mnc) from rabbit blood. Hp solutions of density (d) = 1.083 g/ml, 1.119 g/ml and 1:1 mixture of these solutions (final d = 1.103 g/ml) were compared to Ficoll-Paque (Fp, d = 1.077 g/ml) and Lymphopaque (d = 1.086 g/ml). The average leukocyte recovery was: Fp = 26% and Lp = 17%, while that with Hp was: Hp d = 1.083: 41%; Hp d = 1.119: 43%; Hp d = 1.103: 57%. Optimum mnc recovery (76%) was obtained with Hp d = 1.103. Average mnc purity for the various media was: Fp = 88% mnc; Lp = 91%mnc; Hp d = 1.083: 94% mnc; Hp d = 1.119: 93%; Hp d = 1.103: 94% mnc. Contamination was mainly from basophils. Viability was greater than 95% in all cases. Thus, Hp density gradient media provide increased recoveries of mnc from rabbit blood compared to Fp and Lp, while purity is not affected. Rabbit mnc appear to be denser than human mnc, which are recovered in greater numbers using Fp.