Sometimes people have their urine tested to see if they've been using recreational drugs such as cannabis, ecstasy or cocaine.
Testing for these drugs usually starts with test strips, which contain antibodies that the drug being tested for (or the products made when it's broken down) will bind to.
A sample of urine is applied to the test strip and if a certain amount of the drug (or its products) is present a colour change will occur, indicating a positive result. If this first test shows a positive result, a sample of the urine is usually sent for further testing to confirm which drugs have been used. This second test uses GC/MS (just like the test for steroids).
