Swab the collection port of the catheter with an antiseptic swab. Insert a sterile needle and aspirate 3 to 5 mL of urine into the syringe.
Immediately clamp the catheter tubing.
Return one hour later and empty 3 to 5 mL of urine from the drainage bag into a sterile specimen container.
Flush the catheter with 10 mL of sterile water.