Continuous complete collection of uncontaminated urine in conscious rodents.

We describe a novel technique for complete and continuous bladder urine collection in conscious unrestrained rats. After urethral ligation, a silastic catheter is placed through a flexible steel tether, tunneled subcutaneously from the posterior neck area to a suprapubic incision, and inserted and fixed into the exposed urinary bladder. The catheter drains by gravity into a dependent collecting vessel protected from contamination by feces or food.