Overview, alias, medical examination, examination name, classification, examination materials, principles, reagents, operation methods, normal values, significance of test results, related diseases, overview Troponin is a regulatory protein of muscle contraction, which consists of three subunits with different structures, namely Troponin T(TnT), Troponin I(TnI) and Troponin C(TnC). TnI binds to actin at rest and inhibits the ATPase activity of actin. TnC has four binding sites that can bind calcium ions. When it combines with intracellular calcium ions, it can lead to structural changes of the whole troponin. Troponin relaxes actin and allows actin to interact with myosin, resulting in muscle contraction. There are three isomers of troponin, two of which are unique to skeletal muscle and one is unique to cardiac muscle. There are structural differences among the three isomers of troponin. The structure of T and I subunits in myocardium is different from other muscle tissues. Due to the low molecular weight, cardiac troponin T and I(CTnT and CTnI) were 37000D and 24000D, respectively, and the blood drug concentration increased rapidly after the onset. At present, specific antiserum against CTnT and CTnI has been obtained. Immunochromatography and enzyme immunoassay can be used for rapid detection and quantitative determination, which are rapid, sensitive and specific. Alias TnI；; TnT Medical Examination Name Serum TnI and TnT Classification Blood Biochemical Examination >; Protein's blood collection principle (1) Rapid detection of cardiac troponin T and I: The specific antigen (CTnT, CTnI) in the sample was determined by immunochromatography. During detection, the serum sample is dropped into the sample tank, and the sample moves along the test paper membrane by capillary action. If the sample contains specific antigen, a color band appears at the detection site, and there should be another color band in the control area as the experimental control. (2) Determination of cardiac troponin T by ELISA: Under the action of biotin and avidin, double antibody sandwich ELISA was coated with streptavidin-biotinylated anti-TnT monoclonal antibody, and TnT antigen in the sample was reacted with enzyme-labeled TnT monoclonal antibody in turn, and then primers were added. The enzyme catalyzes the substrate to develop color, and the content of CTnT is quantitatively determined by a series of standard curves formulated by TnT standards. Rapid detection reagent (1) cardiac troponin T and I: CTnT immunochromatographic test strip (patented by Debao Lingman Company). CTnI immunochromatographic test strip (imported). (2) Determination of cardiac troponin T by enzyme-linked immunosorbent assay: ① Biotin-avidin CTnT monoclonal antibody coated plate. ② Incubation buffer. ③ Concentrate the washing liquid. ④ Enzyme-labeled conjugate. ⑤CTnT standard. ⑥ Original source: ABTS (diamino 2,2 azide). Operation method (1) Rapid detection of cardiac troponin T and I: ① Open the wrapping paper and mark the sample number. ② Add 5 ~ 6 drops of serum samples to the sample tank. ③ Observe the appearance of the ribbon within 10 ~ 15 minutes. Note: ① Test paper can only be used 1 time, and repeated use is invalid. ② There are no color bands in the test area and the control area of the test paper, and another test paper has no results after repeated tests, so the test paper is invalid. ③ The determination of CTnT and CTnI by immunochromatography is suitable for rapid bedside detection, but it is only qualitative or semi-quantitative. Only quantitative determination is needed to truly understand the severity of the disease and choose treatment measures. (2) Determination of cardiac troponin T by enzyme-linked immunosorbent assay: ① Add 50μl of standard serum, control serum and patient samples into corresponding wells. ② Add 50μl incubation buffer into each well and mix gently. ③ Incubate at room temperature for 60 minutes, then wash for three times, which is completed within 10 minute. Slap the micropores on the absorbent paper hard. To remove residual water droplets. ④ Add enzyme conjugate 100μl into each well and mix gently. ⑤ Empty the incubation solution in the microplate, rinse the micropores with cleaning solution for three times, and pat the micropores hard on the absorbent paper to remove the residual water droplets. ⑥ Add 200μl of chromogenic substrate solution into the corresponding hole, avoid light, gently stir and let stand for 30 minutes. ⑦ Within 65438 00 minutes, the absorbance value (OD value) was measured with an enzyme-labeled instrument at dual wavelengths of 405nm and 630nm. Note: ① It is better to use serum instead of anticoagulant plasma for CTnT to be tested, because anticoagulants such as heparin and EDTA have effects on CTNT. ② Due to the release of CTnT from myocardial cell injury, hemolysis should be avoided as much as possible. If the specimen is hemolyzed, the test results may increase. ③ The prepared incubation solution should be kept at 2 ~ 8℃ and cannot be frozen. ④ Pay attention to whether the reagent fails before the experiment. If it goes bad, the color will deepen. ⑤ In order to improve the reliability of CTnT detection, attention should be paid to the accuracy of the operation process such as adding samples, and it is best to choose dual wavelengths for colorimetric analysis. Normal dry method: TnI negative immunoassay: TNT 0 ~ 0.1.5 μ g/L. The significance of the test results increased: myocardial ischemic injury, such as myocardial infarction, acute angina pectoris, unstable angina pectoris, after cardiac surgery, etc. After myocardial injury, TnI and TnT first appeared in blood and lasted for a long time, so TnI and TnT are more specific and sensitive indicators of myocardial injury, and TnI is more sensitive than TnT. (1) acute myocardial infarction, the blood drug concentration increased rapidly after the onset, GTnT and CTnI exceeded the upper limit of reference value in 3 ~ 6h, and reached the peak value in GTNT 10 ~ 24h, and returned to normal in 10 ~ 15 days. The ratio of Ctni 1.4 ~ 20h reached the peak and returned to normal in 5 ~ 7 days. That is, it appears early, equal to or earlier than CK-MB; It disappears slowly, lasts longer than LD 1, and has a particularly long diagnostic window, which has the advantages of CK-MB and LD 1. The sensitivity of GTnT is 50% ~ 59% (0 ~ 6h), and that of CTnI is 6% ~ 44%. The specific GTnT is 74% ~ 96%, and CTnI is 93% ~ 99%. It is reported that GTnT is more sensitive than CK-MB in diagnosing AMI, but it is reported that GTnT exists in blood samples of patients with renal disease, so its specificity is poor. GTnT is more sensitive to diagnose AMI than LD 1/LD2, and CTnI is not found in the blood of patients with nephropathy and other diseases, so CTnI is the only specific marker of heart damage. Because GTnT and CTnI disappear slowly, they can be used as markers of late myocardial infarction. (2)GTnT and CTnI can be used as indicators of symptoms of myocardial infarction during cardiac surgery. When patients receive arterial bypass surgery, if the contents of GTnT and CTnI increase, it indicates that myocardial infarction has occurred, but the contents of CK-MB have not changed at this time. Related diseases acute myocardial infarction