Performing a urinalysis
This video outlines how to perform the first steps of a urinalysis. These steps include gross examination of the urine (volume, color, clarity), measuring urine specific gravity, dipstick analysis, centrifugation to create a urine sediment, and placing the sediment on a slide for microscopic examination. It does not cover the latter.
Making a line smear
This is a useful technique for preparing smears of urine for cytologic assessment. This is because urine is typically of low cellularity and is an “inhospitable”environment for cells, so they degrade and rupture easily when making standard cytologic smears, such as the “contact”or “squash” smear. The line smear can be done on centrifuged or uncentrifuged urine (we usually do it on the urine sediment after centrifugation to maximize the number of cells we get to look at), unless the urine is very bloody (then we look at direct smears or smears made from unconcentrated urine). Cytologic assessment of urine compliments standard examination of the wet preparation of a urine sediment and allows more accurate evaluation of morphologic features of urothelial and other tissue cells, as well as inflammatory cells and allows for identification of bacteria, which can be readily differentiated from particulate debris based on their color and shape.