There is no difference between HCG stock solution and diluted solution in essence, in terms of test results diluted solution can provide more accurate results, when HCG stock solution is tested, HCG value exceeds 50,000 IU/L, the test result can only show greater than 50,000 IU/L. HCG diluted solution can be specific to the number, such as 50800-51200 IU/L, HCG diluted solution is mostly used for the diagnosis of staph or choriocarcinoma. The diagnosis of membranous carcinoma, because the value of HCG in both diseases can appear abnormally high. Normally when the pregnancy is 8-10 weeks the HCG value is also relatively high and it is necessary to dilute the HCG to detect the specific result. Dilution of HCG is only done to provide a more accurate figure for clinical diagnosis, and it is not necessary to dilute HCG for routine tests.