With the aid of the giemsa banding technique, exact identification of four different chromosome abnormalities has been achieved. In the case of a Dq/Dq translocation carrier, the chromosomes involved were shown to be numbers 13 and 14 [45, XX, D-, D-t(13q 14q)+]. Using the same technique we identified the abnormal chromosomes in a case of translocation Down syndrome [46, XX, t (21q 21q)+-. We were also able to confirm the finding that the Philadelphia chromosome (Ph1) is the one not involved in Down’s syndrome and to show the banding pattern of the extra chromosome involved in trisomy 18 (47, XX, 18+).