YY/T 1524-2017alpha-L-Fucosidase (AFU) assay kit (CNPF substrate method) (English PDF)

3.1 Appearance

The appearance of kit shall meet the following requirements.

a) The components of kit shall be complete and intact; there is no liquid leakage;

b) The text and symbols of package label shall be clear.

3.2 Loading amount

It shall be no less than the marked value.

4.2 Appearance

Take visual examination with normal or corrected visual acuity under natural light, the results shall meet the requirements of 3.1.

4.3 Loading amount

Use general measuring gauge to measure; it shall meet the requirements of 3.2.

4.4 Reagent blank

4.4.1 Reagent blank absorbance

Use reagent kit to test the blank sample; record the absorbance value (A) at the dominant wavelength of the reading point specified in the reagent kit parameters; which shall meet the requirements of 3.3.1.

4.4.2 Reagent blank absorbance change rate

Test the blank sample with kit; record the absorbance value (A) of the reading point specified in the kit parameters; calculate the absorbance change rate (deltaA/min), which shall meet the requirements of 3.3.2.

NOTE. The blank sample can be pure water sample, saline, zero calibration solution, and the like.

4.5 Analytical sensitivity

Test the sample with a known concentration (30±10) U/L of alpha-L-fucosidase by a kit; record the absorbance value (A) at the reading point specified in the kit parameters; convert into 30 U/L sample's absorbance change rate (deltaA/min), which shall meet the requirements of 3.4.

4.6 Linear

4.6.1 Use the low-concentration sample near the lower limit of the linear interval to dilute the high-concentration sample near the upper limit of the linear interval; mix into at least 5 dilution concentrations (xi). Use kit to separately test the above samples; each dilution concentration shall be tested for 3 times; separately calculate the mean value (yi) of each dilution concentration test results. Obtain the linear regression equation by taking the dilution concentration (xi) as the independent variable and the mean value of test result (yi) as the dependent variable. Calculate the correlation coefficient (r) of the linear regression, which shall meet the requirements of 3.5a).

4.6.2 Substitute the dilution concentration (xi) of the 4.6.1 method into the linear regression equation; calculate the relative deviation or absolute deviation between yi test mean and the corresponding estimate, which shall meet the requirements of 3.5b).

4.8.2 Relative deviation

The kit test can be used to evaluate a certified reference material (CRM) of conventional method or other recognized reference materials for 3 times; the test results can be recorded as (Xi); separately calculate the relative deviation (B) as per Formula (4); if all the 3 results meet the requirements of 3.7a), then it can be judged qualified. If the result of greater than or equal to 2 times are not qualified, then it is judged disqualified. If one result does not meet the requirements, then retest for 20 times; separately calculate the relative deviation as per the Formula (4); if the results of greater than or equal to 19 times meet the requirements of 3.7a), then the accuracy shall meet the requirements of 3.7a). Where. Bi - relative deviation; Xi - measurement concentration; T - calibrated concentration of reference material.

4.8.3 Enterprise reference product test

The manufacturer shall provide the enterprise reference product; test according to the routine sample; each sample shall be tested for 3 times; calculate the average value of the measurement results, which shall meet the requirements of 3.7b).

4.8.4 Comparison test

Use no less than 40 human samples of different concentrations within the detection concentration range to conduct a comparison test with a traceable analysis system designated by the manufacturer. Each sample shall be tested according to the requirements of to-be-tested kit and selected analysis system; each sample shall be tested once; use the linear regression method to linearly fit the two sets of results; then obtain the correlation coefficient (r) and slope of linear regression equation; calculate the absolute deviation or relative deviation between the measured value of the to-be-tested kit and the measured value of control system for each sample, which shall meet the requirements of 3.7c).

4.9 Stability

4.9.1 Shelf life stability

Take the sample after the expiration date, test as per the method specified in 4.4, 4.5, 4.6, 4.7.1, 4.8, which shall meet the requirements of 3.8.2.