Hydatidiform Moles: Methods for Culture and Cytogenetic Analyses Lars O. Vejerslev, Niels Tommerup, and Anni Hallberg ABSTRACT: Placental tissue with macroscopic visible vesicles was processed for chromosome anal- ysis. Enzymatic tissue dissociation, culture initiation in Chang's medium, and final culture in a medium with high glucose content were used, which increased the success rate for kar- yotyping from 55% to 93%. Median culture time necessary far obtaining a karyotype de- creased to about 1 week, irrespective of the chromosomal constitution. This was achieved in spite of increasing time for transportation. The metaphases obtained permitted detailed anal- ysis of chromosomal palymorphisms. In 8 of 44 cases, the karyatype was established on short- term culture alone, which proved to be a valuable supplement in this study. INTRODUCTION The observation that malignant change of hydatidiform moles is mainly, if not ex- clusively, a feature of diploid complete moles has increased clinical interest in the cytogenetic investigation of molar specimens. In recent reports [1, 2] it has been suggested that heterozygous, dispermic complete moles may have a higher malig- nant potential than homozygous moles. Thus, karyotyping and genetic marker anal- ysis may be of prognostic, as well as diagnostic, value. The clinical applications, as well as the cancer research aspects of cytogenetic investigation in hydatidiform moles, require an acceptable success rate, a short cul- ture period, and improved quality of chromosome preparations. Modification and combination of techniques described for chorionic villi [3, 4], molar tissue [5, 6], and choriocarcinoma cell lines [7, 8] resulted in considerable technical improve- ments. This report describes the methods applied to samples received in a Danish study of hydatidiform moles and the final method established, which provides fast and reliable results. MATERIALS AND METHODS The observation of macroscopic visible vesicles in evacuated placental tissue elic- ited the transfer of tissue for chromosome analysis. Samples were transported in 10-ml test tubes, preferably three, containing 4 ml medium 199 (Flow) with 0.05 ml heparin and antibiotics. In addition, 5 ml of heparinized peripheral blood were obtained from each parent. Nineteen of the specimens were received within I hour From the Departmentof Medical GeneticsThe John F. Kennedy Institute, Glostrup,Denmark. Address requests for reprints to Dr. Lars O.Vejerslev, Department of Medical Genetics, The John F. Kennedy Institute, GI. Landevej ~, DK-2600 Glostrup, Denmark. Received June 15, 1985; August 12, 1985. 19 © 1986 Elsevier Science Publishing Co,, Inc. Cancer Genet Cytogenet 22:19-27 (1986) 52 VanderbiltAve., New York,NY 10017 0165-4608/86/$03.50