Supplementary Information

Squamous epithelial cell seen in a Gram-stained preparation of urine

The uroepithelium is columnar. In contrast, the epithelial cells seen on the skin are of the squamous type: large and flat. The presence of uroepithelial cells in urine indicates a pathological condition; if squamous epithelial cells are seen the urine is contaminated.

Laboratory diagnosis of urinary tract infections