Serum assay kit Cardiac Troponin I (hs-cTnI) for Automatic immunoassay analyzer in Cardiac Marker

[INTENDED USE]

The kit has been designed for the quantitative determination of  Cardiac Troponin I (cTnI) in human serum.

The method can be used for samples over the range of  0.02-100.00 ng/mL.

【Expected usage】

For the quantitative detection of troponin I (cTnI) in human serum in vitro. Cardiac troponin (cTn) (including cTnI and cTnT) in acute coronary
It also has important clinical implications in the risk stratification of ACS. When the myocardial cell membrane is intact, cTnI and cTnT cannot penetrate the cell membrane and enter the blood circulation, so the blood of healthy people does not contain or contain very low amounts of cTnI and cTnT. , cTnT diffused into the interstitium and appeared earlier in peripheral blood. Cardiac troponin appears earlier (3-12 hours) after the onset, lasts for a long time (4-10 days), and has high sensitivity and specificity for myocardial injury. It is currently the best definite marker for the diagnosis of AMI thing.

Troponin I is a specific and sensitive marker for detecting myocardial injury. Elevated levels of troponin (above the cutoff value) within 4-12 hours of acute myocardial ischemia have high specificity and sensitivity for the diagnosis of acute myocardial infarction. According to the ESC and ACC Common Protocol - Redefinition of Myocardial Infarction (which gives the definition of myocardial infarction and the reliability of cTnl assays), AMI is defined as: Troponin I concentration exceeding the 99% confidence interval of the reference control group Any case of standard thresholds. Therefore, the acceptable (total) imprecision at the 99% confidence interval for each assay should be defined as: no more than 10%. Troponin concentrations peak within 14-36 hours of acute infarction and remain high for 7 days. Serial testing of troponin I concentrations is recommended in patients with suspected myocardial injury.

At the same time, cTnI is the preferred marker for risk stratification, and if feasible, all patients with suspected ACS should be tested for cTn. In patients with clinical symptoms consistent with ACS, a peak cTn value above the 99th percentile of the normal reference population is predicted to be at increased risk of death and recurrence of ischemic events.

The current clinical and laboratory determination methods for troponin I include enzyme-linked immunosorbent assay, colloidal gold method, fluorescence immunoassay, and chemiluminescence method.

【Inspection Principle】

This kit adopts the principle of direct sandwich method, uses magnetic microparticles as the solid phase of immune reaction, and uses chemiluminescence enzyme-linked immunoassay method and chemiluminescence measuring instrument to detect the content of cTnI in human serum.

The technical principle is: Fluorescein isothiocyanate (FITC)-labeled mouse monoclonal anti-cTnI antibody and alkaline phosphatase (AP)-labeled paired mouse monoclonal anti-cTnI antibody and samples, calibrators or quality controls. cTnI binds to form a "sandwich" complex. Subsequently, the magnetic particles linked with goat anti-fluorescein isothiocyanate (FITC) antibody were added, and the antigen-antibody immune complexes were bound to the magnetic particles through the specific binding of the anti-FITC antibody to FITC.

Under the action of an external magnetic field, the complex formed by the immune reaction is separated from other unbound substances, and after washing the complex, an enzymatic chemiluminescent substrate (adamantane derivative) is added. The substrate is catalytically cleaved under the action of the enzyme to form an unstable excited state intermediate.

When the excited state intermediate returns to the ground state, photons are emitted to form a luminescence reaction, and the luminescence intensity of the reaction can be detected by a chemiluminescence instrument. In the range of measured wavelength (230-700nm), the luminescence intensity is proportional to the content of cTnI in the sample, and the cTnI concentration in the sample can be calculated by fitting the modified four-parameter Logistic equation.