Collect urine samples: it seems simple, but one has to pay more attention to it. Incorrect method can lead to incorrect result like false positive or false negative.
Time: the urine excreted at any time can be used for examination. We usually collect the first time urine in the morning, for the urine is pure and can reflect the true ill condition. Even if the morning urine can not be collected, one should not drink water and milk before the collection.
New：The urine have to be handed in for examination in two hours. If the urine has been stored for a few hours, the glucose in urine would be degraded, the cast would be damaged and cytolysis would happen, which would affect the correct result.
Middle part urine: according to the urination time, urine is divided into forepart, middle part and end part. As the forepart and end part are easily contaminated, the middle part is chosen for examination.
Female patients should avoid examination during her period when collecting the urine samples and she should clean her vulva. Otherwise, leucorrhea and blood in the urine would affect the result. Male patients should not contaminate the urine with prostatic fluid.
Urine volume: usually the urine volume in need is 5-10ml; 50ml urine is needed for the urinometer test.
