Cryptococcus causes mainly central nervous system, pulmonary and cutaneous lesions, which can be life-threatening in severe cases. Disseminated lesions can also occur in the ends of long bones, joints, liver, spleen, kidneys, heart, testes, prostate, and other organs. Typically, affected tissues contain peptide-like yeast cysts, which are formed by the accumulation of polysaccharides in the cryptococcal cyst membrane, but have only mild or no acute inflammatory changes. In severe cases, sepsis may occur and spread to all organs of the body or even cause death. So what are the laboratory tests for cryptococcal cysticercus polysaccharide accumulation? Here is a brief introduction. Laboratory tests: Since Cryptococcus is a fungus, the phase contrast microscopy method can be used to find the pathogen. 1, the pathogen examination ① ink staining method: is a rapid, simple and reliable method, according to the different parts of the damage to take the fresh specimens required for examination, such as cerebrospinal fluid, sputum, focal tissue or exudate, etc., placed on a slide, add 1 drop of ink, covered with a coverslip, and look for cryptococci in the dark field of the microscope, which can be seen as a round body, with a transparent circle of fat pods on the outer axis, with reflective spores inside, but no mycelium. Repeat several times to find high positive rate, cerebrospinal fluid should be centrifuged to take precipitate smear. ② fungal culture: take a small amount of specimens placed in the sand medium, at room temperature or 37 ℃ culture 3-4 days visible colonies grow out. 2, serological examination Because there are not many detectable antibodies in the patient’s serum, so the detection antibody positive rate is not high, specificity is not strong, only for counselling diagnosis. Usually the detection of new cryptococcal podococcal polysaccharide antigen, latex agglutination test is inspired and specific, and has the role of estimating the prognosis and efficacy.