The skin test solution for ampicillin needs to be prepared at a ratio of 0.05 mg of ampicillin sodium per 1 ml of fluid by taking 1 g of ampicillin sodium, adding 4 ml of saline, then 0.1 ml of the upper fluid after preparation, adding saline to 1 ml, then 0.1 ml of the upper fluid after preparation, adding saline to 1 ml,then 0.2 ml of the upper fluid after preparation, adding saline to 1ml can be. Ampicillin sodium, also known as ampicillin, belongs to the penicillin class of antibiotics, is a commonly used antibiotics in the clinic, in order to avoid allergic reactions to the drug, so it is necessary to carry out a skin test test before use, the skin test is negative, it indicates that the patient is not allergic to this drug, you can continue to use it to fight infection, if the skin test results are positive, then the patient can not use this drug. If the skin test is positive, the patient can not use this drug. For the treatment of disease which antibiotics to choose, should be under the guidance of the doctor according to the results of the culture of pathogens to choose.