A pipette method for rapid karyotyping in prenatal diagnosis

The "pipette method' is introduced as a method of prenatal diagnosis which is in competition with the "in situ' and the "trypsinization' technique. It is sufficiently standardized for routine diagnosis and the banding techniques currently used in prenatal diagnosis (G, Q, C-banding and NOR) have been adapted for it. In 180 cases from 27 different centres, the "pipette method' was employed for chromosomal harvesting in order to save time. An average of 6 X 6 days was taken to achieve a result. There was a pathological karyotype in 28 cases (16.1 per cent) and this high proportion can be related to cases where ultrasound scan has led to a diagnosis of "suspected chromosomal abnormality.' This technique is also of use in advanced stages of pregnancy. The early recognition of the fetal karyotype can contribute to the future management of the pregnancy. The "pipette method' can also be used in chromosomal harvesting of tumour cells and fibroblast cultures.