Surface immunoglobulin on rabbit lymphoid cells. V. Ultrastructural distribution of b4 allotypic determinants of thymus, lymph node and bone marrow lymphocytes.

An indirect immunoferritin-labeling technique is used to localize cell surface immunoglobulin (Ig) allotypic determinants on rabbit lymph node, bone marrow and thymus lymphocytes. 47% of the lymph node cells, 62% of bone marrow small lymphocytes and less than 1% of thymic lymphocytes, are positive for surface Ig. Two Ig-positive lymph node lymphocyte populations which differ in fine structure are identified but both cell types express similar amounts of surface Ig (7,000-28,000 Ig molecules per cell). Bone marrow small lymphocytes make up only 9% of the total cell population and express less surface Ig (ca. 3,000-12,000 molecules Ig per cell) than most Ig-bearre described and both are essentially negative for surface Ig using this labeling technique.