Enzyme-linked immunosorbent assay (ELISA) is an assay based on the specific reaction between antigen and antibody. False negatives may occur when reagents are improperly stored, when there are operational errors, when the reagents are not qualified, or when the results are incorrectly determined. 1. Improper storage of reagents: If the reagents for ELISA are not stored properly, the activity of antigen or antibody may be reduced or even inactivated, resulting in false negative results. 2. Operational errors: If there are operational errors in the ELISA test, false negative or false positive results may also occur. 3. Unqualified reagents: If the reagents are low or inactive antigens or antibodies are encapsulated in the kit during the production process, it may lead to inaccurate results. 4. Incorrect determination of results: If the test results cannot be determined correctly after the experiment, it may also lead to errors in the determination of results and false negative or false positive results. If the results are abnormal when performing the immunosorbent assay, it is necessary to consult a doctor in time and perform the operation and interpretation of the results under the guidance of a professional doctor.