Fractionation of cytotoxic T lymphoblasts on Ficoll gradients by velocity sedimentation

Velocity sedimentation of lymphoid cells on linear Ficoll gradients in polycarbonate tubes provides a simple reproducible technique for fractionating lymphocytes from lymphoblasts. Using this method the T lymphoblast was characterized as an important cytotoxic cell in the early immune response to the H‐2d alloantigen of the P‐815‐Y mastocytoma, and at a later time the small lymphocyte was shown to be the predominant cytotoxic cell. Enrichment and depletion of cytotoxic lymphocytes was also demonstrated in fractionated spleens.