Immunosuppressive Method - Activity Assay
By inhibiting the CK-M subunit, the catalytic reaction rate of the remaining CK-B subunit is measured. Since the content of CK-BB in serum is extremely low and can be ignored, the measured activity of the B subunit is multiplied by 2 to indirectly calculate the activity of CK-MB.
● Advantages:
Fast detection speed, low equipment cost, and economical testing expenses, making it suitable for routine screening of myocardial injury.
● Disadvantages:
High false-positive rate, susceptible to interference from CK-BB, CK-MM, macro-CK, and other factors.
● Interfering Factors:
Elevated CK-BB levels, excessively high total CK activity, macro-CKemia, sample hemolysis, heterophilic antibodies (HA), etc.
Latex Immunoturbidimetry - Quantitative Assay
The CK-MB in the sample reacts with the specific antibody against CK-MB coated on latex particles to form immune complexes, and the absorbance change is detected at a specific wavelength. This method has the advantages of high specificity, high sensitivity, and strong anti-interference ability, which can more accurately reflect the status of myocardial injury.
● Advantages:
High specificity, sensitivity, and precision; superior stability; greater predictive value for diseases.
● Disadvantages:
Slow detection speed; high requirements for equipment; high testing costs.
● Interfering Factors:
The quantitative assay of CK-MB relies on antigen-antibody reaction principles, featuring high immunological specificity. It can exclude multiple interferences (avoiding cross-reactions with CK-BB and interference from drugs, proteins, etc.).