Metaphase synchronization and chromosome preparation from the OK opossum cell line having a potentially isolatable X chromosome.

As part of a study on X chromosomes, metaphase cell synchrony and chromosome isolation methods were developed for the opossum (Didelphis virginiana) kidney epithelial cell line (OK). The cell synchrony yielded large amounts of metaphase cells using a relatively simple method in which a key feature was a calcium- and magnesium-free balanced salt wash. A neutral pH chromosome isolation method was developed for the kidney epithelial cells, because they were somewhat difficult to disrupt fully by other methods. FACS IV flow microfluorometric analysis of OK chromosomes confirms a clear difference between the sizes of opossum X chromosomes and autosomes.