Before measuring blood glucose with a blood glucose meter, it is necessary to sterilize the area with alcohol, usually using a second drop of blood, mainly to avoid the influence of alcohol or blood collection needles on the blood, so as to make the measurement results more accurate. According to the operation standard of blood glucose test, before using blood glucose meter to measure blood glucose, you need to use 75% ethanol to disinfect the site of blood collection, and wait for the ethanol to air-dry before blood collection. Generally, the first drop of blood should be swabbed with a sterilized cotton ball, and then the second or third drop of blood should be used for fingertip blood glucose measurement, mainly to avoid the influence of alcohol or blood collection needles on the blood. In addition, the fingertip skin should not be squeezed excessively after puncture to avoid mixing of tissue fluid into the blood, resulting in biased results.