A new and simple technique for chromosomal preparations from peripheral blood lymphocytes, amniotic cell cultures, skin fibroblasts, bone marrow and single cell clones when the yields from harvests are low.

A technique for chromosomal preparations from low yields harvest is presented using Poly-L-Lysine (300,000-400,000 MW). The procedure can be successfully used for peripheral blood lymphocytes, amniotic cell cultures, skin fibroblasts, direct preparations from bone marrow, cloned clusters and colonies from bone marrow grown on agar or methyl cellulose and eggs and blastocysts, with applications to other tissues. The technique is simple with minimal cell loss, and chromosomal preparations of good quality can be obtained which are amenable to all banding techniques.