For a urine culture, the first morning sample is best collected into a sterile container and dropped off at the lab as soon as possible. Most labs ask for it within 1 to 2 hours if kept at room temperature.
Next Steps
If you can't reach the lab that quickly, refrigerating the sample (not freezing) can keep it usable for a few hours longer. Please check with your physician if the urine culture was advised alongside any symptoms that need a closer look.