Blood culture is a test method to observe whether there is colony formation by drawing peripheral blood from a patient and culturing it in a culture flask, which is often used clinically for the diagnosis of patients with unexplained long-term fever. Blood culture is usually done for aerobic bacteria culture, anaerobic bacteria culture, fungal culture, etc. By blood culture, if colony formation is found, it is possible to determine which type of bacterial infection is present. Blood culture is often done at the same time drug sensitivity test, if the pathogenic bacteria are found, through the drug sensitivity test can also find out which type of antibacterial drugs are sensitive to the bacteria. Therefore, through blood culture, it is often possible to find out which bacteria are infecting the human body and to discover targeted antibacterial drugs. Once a sensitive antibacterial drug is found, clinical guidance can often achieve better treatment results. However, leukemia patients often have difficulty finding a positive result in blood culture due to the reduced white blood cell count after chemotherapy, even though they have obvious symptoms of bacterial infection.