Levy-Jennings Experiments in mapping the purpose of quality control
Levy-Jennings Experiments in mapping the purpose of quality control
1、To clarify the significance of indoor quality control of clinical biochemistry. 2、To master the drawing of Levy-Jennings quality control chart and the interpretation of the results and the analysis of the reasons for the loss of control. This experiment is from the laboratory guide of 5-year undergraduate testing program of Mudanjiang Medical College.
Operation method
The Levy-Jennings Quality Control Purpose Mapping Experiment Move l. Calculation of OCV and RCV: Under the conditions of OCV and RCV, respectively, the same batch of quality control serum is measured not less than 20 times, and the mean value is calculated. Standard deviation. Coefficient of variation. For more product details, please visit Aladdin Scientific website.
2. Plotting:
(1) Mark X. X + 2SD. X + 3SD in vertical coordinates and mark their specific values on the left coordinate scale.
(2) With a red pen to draw the X + 2SD line, with a blue pen to draw the X + 3SD line that is an OCV (or RCV) of the empty map. Which each cell represents SD / 10, and should also be added to the top of the drawing of the items: experimental items. Unit of measurement. Serum source and lot number. Start and end dates. Main instruments and wavelengths used.
(3) Date at the bottom of the drawing. The same value. Operator to add the appropriate content according to the original record. Date column, in the OCV measurement, should be changed to test batch (or serial number). Did not do the determination of the holiday, Sunday in the chart to do space processing.
(4) Draw the points of the graph corresponding to each test value: the horizontal coordinate on the graph is its date, and the vertical coordinate is the measurement value.
Out-of-control treatment:
1. briefly and quickly review the entire operation, analyze the steps most likely to be in error, and check that the calculations are correct. If the operation was performed manually, check that the pipette was not used incorrectly, that the instrument functioned correctly, that the colorimetric cup was clean, etc.
2. If there is no error in the above, repeat the measurement with the quality control serum to see if there is any improvement in the result, if there is any improvement, it means that the error is likely to be caused by the operation error. If there is an improvement, the error is probably due to operational errors, such as adding the amount of specimen. If there is any improvement, it means that the error is probably caused by the operation error, such as the wrong amount of specimen, the wrong amount of reagent, the wrong choice of wavelength or filter, etc.
3. If the result is still not within the permissible range after redoing, redo the test with a new bottle of quality control serum. Observe whether the result can be corrected.
4. If the problem still cannot be solved, use the fixed serum and the quality control serum to measure at the same time. If the result is satisfactory, the original batch of quality control serum has been deteriorated or contaminated.
5. If the problem still can not be solved, the instrument should be recalibrated, or replace the new standard solution and reagents, and then re-operate to find the cause.