What's a mid-stream urine sample?
A mid-stream urine sample means you don't collect the first or last part of urine that comes out. This reduces the risk of the sample being contaminated with bacteria from:
What urine samples are used for
Your GP or another healthcare professional may ask for a urine sample to help them diagnose or rule out certain health conditions.
Urine contains waste products that are filtered out of the body. If the sample contains anything unusual, it may indicate an underlying health problem.
Urine tests are most commonly carried out to check:
Collecting a urine sample
Your doctor or another healthcare professional should give you a container and explain how you should collect the urine sample.
You can collect a urine sample at any time of day, unless your GP or practice nurse advises you otherwise.
The types of urine sample you might be asked for include a random specimen, first morning specimen or timed collection.
To collect a clean urine sample:
label the container with your name, date of birth and the date
wash your hands
start to urinate and collect a sample of urine "mid-stream" in a sterile screw-top container
screw the lid of the container shut
wash your hands thoroughly
Follow any other instructions your doctor gives you.
Storing a urine sample until you hand it in
If you can't hand your urine sample in within an hour, you should keep it in the fridge at around 4C (39F) for no longer than 24 hours. Put the container of urine in a sealed plastic bag first.
The bacteria in the urine sample can multiply if it isn't kept in a fridge. If this happens, it could affect the test results.