Chromatin pattern of isolated human small thymocytes. A morphometric and stereologic study.

Human small thymocytes, isolated by the unit gravity velocity sedimentation technic, were analyzed in ultrathin sections to define their chromatin pattern using morphometric and stereologic methods. Condensed chromatin in these cells represents about 70% of the nuclear volume and, is distributed in peripheral (75%) and central clumps (25%). The analysis of the distribution pattern of these clumps shows that peripheral clumps are distributed more irregularly than central clumps with respect to both size and relative position. Comparison of these results with those previously described for human peripheral blood T lymphocytes shows significant differences, probably related to the different maturation states of the two cell types.