Basic Performance of In Vitro Diagnostic Reagent Products

1. Blank IVD in vitro diagnostic reagents

The reagent blank can be understood as the value detected when the content of the substance to be tested is the theoretical zero value. The general practice is to measure water as a sample, and theoretically this value should be zero. But the actual situation is not the case. Even if the added sample is water, it will show a certain degree of reactivity. A constant blank reactivity does not affect the performance of the reagent. However, if the blank reactivity fluctuates greatly, it may lead to inaccurate clinical results. The instability of the reaction system of the reagent, such as the instability of the preservative system, buffer system, and enzymatic reaction system, will lead to changes in the blank reaction degree.

2. IVD in vitro diagnostic analysis sensitivity

Analytical sensitivity refers to the slope of the calibration curve (or analytical curve), which can reflect the sensitivity of IVD in vitro diagnostic reagents to changes in the content of the substance to be tested. If the sensitivity is higher, corresponding to the same amount of change in the content of the substance to be tested, the change in the detected experimental value will be greater. In this way, even a small change in the content of the substance to be tested can be easily detected.

3. Linear range of IVD in vitro diagnostics

If within a numerical interval, the content of the substance to be tested is in a good one-to-one proportional relationship with the value of the analysis and detection, then we can call this numerical interval the linear range of the diagnostic reagent. The wider the range of values covered by the linear range, the wider the coverage of clinical samples. Two diagnostic reagents that detect the same analyte, reagent A has a linear range of 0 to 100, and reagent B has a linear range of 10 to 90; then reagent A will be more popular because it takes care of those samples of 0 to 10 and 90 to 100, no need to think of ways to retest separately, saving time and energy.

4. Specificity of IVD in vitro diagnostic analysis

IVD In vitro diagnostic assay specificity refers to the ability of the test results of the analyte to be free from interference from other components. In other words, the test results of diagnostic reagents will be affected by the presence of some substances, resulting in deviations from the actual situation. Common interfering factors include hemolysis, blood lipids, bilirubin and VC.

If the test results are not affected at all, unless these substances are not present in the human body, they are interferences for diagnostic tests, but they are components to maintain human body functions, so it is impossible to do without them. In this case, only the diagnostic reagent itself can overcome the difficulty. How to overcome it? Improve your own anti-interference ability. If the diagnostic reagent can control the deviation between the test result and the actual value within an acceptable range in an environment where a large amount of interfering substances exist, then the anti-interference ability of the reagent will pass the test.

5. IVD in vitro diagnostic stability

Stability can be understood as the shelf life of IVD in vitro diagnostic reagents, ensuring that the test results of the reagents are stable and reliable within a certain period of time. Stability can be divided into long-term stability and bottle-opening stability. Let's take canned food as an example. If a can manufacturer states that the can is safe to eat for three years as long as the can is unopened, that three-year period represents long-term stability.