Attmepts to induce chromosomal breakage in chicken embryos with Aroclor 1242

Fertile White Leghorn eggs were injected with Aroclor 1242 and incubated for four to five days. More than 65 percent of the exposed embryos died prior to examination at the end of the incubation period. The five largest pairs of chromosomes from allantoic squashes were examined for the presence of chromosomal breakage in 753 metaphases from PCB-treated eggs and 196 metaphases from controls. Failure to detect chromosomal aberrations in either group indicated that Aroclor 1242, in concentrations of 10 p.p.m. or 20 p.p.m. in the egg, is not an effective clastogen in the chicken embryo.