An enzyme-linked immunosorbent assay (ELISA) for the detection of monoclonal antibodies recognizing surface antigens expressed on viable cells.

A solid-phase enzyme-linked immunosorbent assay (ELISA) has been developed for detecting monoclonal antibodies binding to surface antigens expressed on viable adherent cells of tumor cell lines. This assay utilizes a sheep anti-mouse IgG to which a beta-galactosidase is linked. It is highly sensitive and permits quantification of IgG monoclonal antibody levels.

Identification of a p69,71 complex expressed on human T cells sharing determinants with B-type chronic lymphatic leukemic cells.

In the course of generating monoclonal antibodies to human thymus-dependent differentiation antigens, we were able to define specificities shared by T cells and by cells from patients with chronic lymphatic leukemia that were not detectable on normal B cells. In particular, one of these antibodies was reactive by indirect immunofluorescence with greater than 95% of the thymocytes and 80--95% of nonadherent sheep erythrocyte-rosetting peripheral blood lymphocytes (PBL), but was unreactive with normal B cells or cell lines derived from PBL by Epstein-Barr virus transformation. However, the leukemic cells from 11 of 14 patients with B-type chronic lymphatic leukemia were found to express detectable concentrations of this surface determinant.

Potentiation of radiation effects in hypoxic HeLa cells.

HeLa cells were irradiated with two doses of gamma rays: the first dose was delivered under hypoxic conditions and the second dose was delivered under oxygenated conditions. Increased inactivation of cellular proliferative capacity as a function of intervening time was obtained when hypoxic conditions were maintained between doses. Hypoxic protection from ionizing irradiation can be counteracted by manipulating postirradiation conditions.