CPT Code


Specimen Type


Container Type

Serum Separator Tube (SST)/Yellow


Room Temperature, 7 days; 2-8° C, 7 days; -20° C, 1 year

Handling Instructions

Allow to clot for 30 mins, centrifuge within 2 hours

Clinical Notes

As the test name indicates, a BUN test measures urea nitrogen in the blood. Urea, often called urea nitrogen, is a waste product that is produced as a result of the breakdown of proteins in the body. The kidneys work to filter urea out of the blood so that it can be cleared out of the body in the urine. As this process unfolds, it’s normal for some urea to be in the blood. But when BUN levels are too high, it can be an indication that the kidneys are not functioning properly.

Performing Lab

Principle Laboratory - Dallas
6210 N Belt Line Rd
Irving, TX 75063

Principle Laboratory - Houston
16840 Buccaneer Ln
Suite 281
Houston, TX 77058