ICS Result and Reaction Principle
The serum was diluted with the sample diluent at a ratio of 1:10, and then 100 μL of the diluted sample solution was dropped onto the sample pad to observe the results within 5–10 min at room temperature. If the test and control lines appeared red, the test was positive; if the test line did not appear red, and the control line appeared red, the test was negative. If the control line was not colored, the test was deemed invalid (Figure 7B ).
When the serum to be tested is added to the sample pad, it migrates forward by capillary action. If the serum reaching the conjugate pad contains p30 or p72 antibodies, the protein on the conjugate pad reacts with its corresponding antibody, thereby forming the corresponding antigen-antibody complex. It continues to migrate to T2 (p30) or T1 (p72) to form a red band visible to the naked eye. Regardless of whether the serum to be tested contains p30 and p72 antibodies, the gold-labeled protein will continue to migrate to the control line and react with the anti-p30 and -p72 monoclonal antibody complexes at the control line to produce a red band visible to the naked eye. Therefore, if the red bands are not displayed during the quality control assessment, the test strip is rendered invalid.