I. Intra-lot reproducibility test

Purpose: To examine the random error of the experimental method and evaluate the precision of the method.

II. Recovery test

Purpose: To detect the proportional systematic error to measure the accuracy of the analytical method .

III. Interference test

Purpose: to examine the constant systematic error of the method to evaluate the accuracy of the candidate method

This experiment is derived from the experiment guide of Mudanjiang Medical College, undergraduate 5-year testing program.

Operation method

Experiments in methodological evaluation

Move

I. Intra-lot reproducibility test

1. Repeat the determination of the same sample 20 times within a short period of time in accordance with the prescribed method.

2. Statistical processing: the results of the measurement. Calculate the mean value (X), standard deviation (SD), coefficient of variation (CV) according to the following formula.

X = ∑X/n SD = ∑(X-X)2/n-1 CV = SD/Y × 100%

3. Evaluation: general analysis CV value less than 50%, precision analysis CV value less than 2

Recovery test

1. Sample preparation:

Base sample: serum 2.0ml + distilled water 0.1ml

Low concentration recovery sample: serum 2.0ml + 4mmol/L calcium standard 0.1ml

High concentration recovery sample: serum 2.0m1 + 25mmo1/L calcium standard solution 0.1m1

2. Calculate the added concentration according to the following formula

Addition concentration = standard solution concentration × standard solution volume / serum volume + standard solution volume

3. Measure the concentration in each sample tube more than 3 times.

4. Calculation. Calculate the sample recovery concentration and recovery rate separately

5. Recovered Concentration = Measured Concentration of Recovered Sample - Measured Concentration of Base Sample

Recovery rate = Recovered concentration / added concentration x 100%.

III. Interference test

1. Sample preparation:

Base sample: blood please 1.8m1 + 0.2ml

Low concentration recovery sample: serum 1.8m1 + 63umol/L creatinine standard 0.2ml

High concentration recovery: serum 1.8m1 + 414umol/L creatinine standard 0.2ml

2. Calculate the added concentration according to the following formula

Addition concentration = standard solution concentration × standard solution volume / serum volume + standard solution volume

3. Calculate the concentration in each sample tube

4. Calculate the interference value:

Interference value = measured concentration of interfering sample - measured concentration of interfering sample

5. How to eliminate the interference (discussion)

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