| Abstrakt: |
A method of immune adherence applicable to tissue culture cells in monolayers is described. It is some twenty times more sensitive than cytotoxicity (dye-exclusion) as a quantitative immunoassay, applicable to the antigens of the cell surface. It has been found that adherence does not occur to confluent cell sheets, and this can be explained if immune adherence to tissue culture cells occurs only at the tips of pseudopods. This source of variation can be reduced to a minimum by the use of sparse cell layers, and under suitable conditions the antiserum titres obtained do not vary by more than one doubling dilution. With the aid of this method, the antigens of BHK21 hamster kidney cell surfaces have been studied after transformation by polyoma and other viruses. Using rabbit antisera, it was found that Forssman antigen, which is absent from BHK21 cells, appeared on the surfaces of all the transformed lines studied. Rous virus-transformed BHK21 cells also showed this antigen, and reversion to the normal cell morphology, which occurs in these lines, was accompanied by a loss of this antigen. |
