Lifesign 60101 - LifeSign MI Troponin l (TnI) Test Kit, 20Tests, 1/BX
LifeSign MI Troponin l (TnI) Test Kit
For The Rapid Qualitative Detection Of Cardiac Markers. To Aid In The Diagnosis Of Acute Myocardial Infarction
- MODERATELY COMPLEX
- Qualitative Troponin I
- Enables prompt emergency room decisions
- Easy to use procedure; Add 3 drops of specimen into device
- Read results in 15 minutes
- Improves patient care
- Reduces unnecessary testing and admissions
Intended Use of LifeSign MI Troponin
For the rapid qualitative detection of cardiac troponin I (cTnI) in human whole blood, serum and plasma as an aid in the diagnosis of myocardial infarction in emergency room, critical care, point-of-care, and hospital settings. The LifeSign MI Troponin I Assay provides a qualitative analytical test result. The qualitative nature of this assay does not provide information about change - either the rise or fall - in the concentration of cTnI with single testing. A quantitative method should be used, if desired, to determine the concentration of cTnI at any given time. Only with serial testing could a temporal change in the level of cTnI be concluded. Clinical consideration and professional judgement should be applied when interpreting the results of the LifeSign MI Troponin I Assay, especially when single testing results are used.
Summary and Explanation of LifeSign MI Troponin
The troponin complex is formed of three subunits, troponin T (TnT), troponin C (TnC) and Troponin I (TnI). The three troponin subunits have distinct functions with TnC as the Ca++-binding, TnT as the tropomyosin binding, and TnI as the inhibitory subunits.1 The troponin complex, together with tropomyosin, form the main component that regulates the Ca++-sensitive ATPase activity of actomyosin in striated muscle (skeletal and cardiac).2 Different isoforms of TnI exist in the skeletal and cardiac muscles (sTnI and cTnI, respectively) with distinct structural heterogeneity between these isoforms that allow the production of isoform-specific antibodies.3 These isoform-specific antibodies have been utilized to assemble various detection methods that are isoform-specific. Recent reports have investigated the utility of determining the serum levels of the different isoforms of TnI.
Detection of cTnI in the serum was investigated as an aid in the determination of myocardial damage in patients with acute myocardial infarction (AMI).5 Several clinical reports have demonstrated the diagnostic value of determining the serum level of cTnI in identifying patients with AMI. The temporal relation of release of cTnI into the serum has been investigated and compared to the other established cardiac markers such as CK-MB, myoglobin and TnT. Cumulative data from several reports documented that in patients with AMI, cTnI is released into the circulation with levels exceeding the upper reference limit of normal 4-6 hours after the onset of symptoms and peak levels are reached after 12-24 hours.8 This early release profile is similar to CK-MB. However, CK-MB levels return to normal values after 72 hours, while levels of cTnI remains elevated for up to 5-7 days. Due to the distinct structure of cTnI and the availability of highly-specific detection methods for cTnI, the utility of this marker for the diagnosis of AMI in complex clinical conditions that involve skeletal muscle damage have been investigated. The high specificity of cTnI measurements for the identification of myocardial damage has been demonstrated in conditions such as perioperative period, after marathon runs, and blunt chest trauma.8,9,10 The release of cTnI into blood has been documented in clinical conditions that involve myocardial damage, other than AMI, such as unstable angina, congestive heart failure, and ischaemic damage due to coronary artery by-pass surgery. Measurements of cTnI have been investigated and documented to be valuable in identifying patients with AMI presenting to the ED with 1 chest pain.
Principle:
The LifeSign MI Troponin I Test employs solid-phase chromatographic immunoassay technology to qualitatively detect the presence of cTnI above an established cutoff level in human blood, serum and plasma samples. After a specimen has been dispensed into the sample well, plasma or serum is transferred into a region containing monoclonal anti-cTnI antibody-dye conjugates and rabbit polyclonal anti-cTnI antibodies. These antibodies bind to cTnI in the sample to form complexes, which migrate through the reaction strip. The antigen/antibody dye complexes are then captured by immobilized avidin in the TnI area. Additional protein-dye conjugates not bound in the Test (TnI) area are later captured in the Control (C) area.
Visible purplish horizontal bands will appear in the TnI and C areas if the level of cTnI is above the established cutoff level. A visible purplish band in the C area indicates the assay is working properly. If a band is present only in the C area, the result is read as negative, indicating that the level of cTnI is below the cutoff level. If no band is present in the C area, the test should be considered invalid and another test must be run, regardless of the presence or absence of a band in the TnI area
LifeSign MI Troponin I Test Procedure and Results
Interpretation of Results
The color intensity of the TnI and C bands may increase beyond 15 minutes. As the membrane in the reading window dries up, changes in the intensity of the bands and background may interfere with reading the test results. For best results, the test should be read at 15 minutes.
Positive (+): The presence of two colored bands, one in the TnI area and the other in the C area, indicates a positive result.
Notes:
- A positive test result can be read as soon as a distinct purplish colored band appears in both the TnI and C areas.
- Positive test results from strong positive samples may appear within 5 minutes.
- The TnI band will appear before the C band in most strong positive cases. The TnI band may be darker than the C band.
- The TnI band may appear after the C band in weak positive cases, and the TnI band may be weaker than the C band.
The LifeSign MI Troponin I Test has been optimized to have a minimal prozone effect. Therefore, a sample containing a very high concentration of cardiac troponin I might produce a somewhat weaker signal than expected but would still produce a positive result. The test does not require any sample dilution, but it is recommended that the sample be diluted with a separate negative sample and retested to confirm the result in case a prozone effect is suspected.
Negative (-): A single colored band in the C area, with an absence of a distinct colored band in the TnI area, indicates that the concentration of cardiac troponin I is below the established cutoff value.
Invalid: A distinct colored band in the C area should always appear. If no purplish band is present in the C area within 15 minutes, the test is invalid, and the sample should be retested using a new Card Test
