Selection of Hybrids from Matings of Fibroblasts in vitro and Their Presumed Recombinants

When two clonal lines of mouse fibroblasts, each containing a drug-resistant marker, are grown together for 4 days, hybrid cells can be detected by selective conditions. These hybrid cells are presumed to be the result of mating. By the same method evidence can be obtained which suggests that mating may be followed by segregation.