Human epithelial cells cultured from urine: growth properties and keratin staining.

Epithelial cells can be cultured from the urine of newborn infants, providing a simple, noninvasive biopsy method. We established such cultures by standard techniques from 44% of uncontaminated specimens obtained from newborn infants up to 1 week of age. There was an average of three colonies per milliliter of urine. Many cultures accomplished 15 to 25 population doublings in as many as five subcultures and yielded total potential culture sizes of 10(4) to 6 x 10(8) cells. Plating efficiency was high at each passage. The cultures displayed two morphologically distinct epithelial cell types. Immunofluorescent staining of keratin fibers in most of these cells further identified them as epithelial.