1. The significance of calibration of biochemical analyzer

Calibration is to find a reference point, which is a K value (or F value). It is determined by the state of the instrument and reagents. When we measure a specimen, whether you use a manual method or an automatic biochemical analyzer, the measured value is just an absorbance, which has no meaning to us. We have to convert this absorbance into a concentration or enzyme activity . Then multiply it by a K value, and the calculated and printed result is meaningful to us. The K value is what we find out through calibration. Generally, the minimum requirement is to have reagent blank and standard, and two absorbances measured by the instrument:

K=(standard concentration-reagent blank)/(A standard-A reagent blank)

(Reagent blank is usually 0)

We know the concentration of the standard solution, and these two absorbances can be measured by the instrument, so that a K value is obtained. No matter what kind of specimen, we can get the answer by multiplying its absorbance by the K value. Therefore, the K value has a very decisive significance and can determine the accuracy of the specimen.

2. The determinants of K value

Let's see how the K value will be affected? First, the concentration of the standard solution must be accurate (the standard solution is best to use serum as the matrix as the specimen). Second, the absorbance of the standard solution and the absorbance of the reagent blank must be accurate. The absorbance is affected by the condition of the instrument and the condition of the reagents. If your instrument is fairly stable, reagents are a major factor affecting the K value.

3. How to determine the K value is correct?

We generally use quality control serum for inspection, preferably two levels of quality control serum for inspection. If the quality control results are good, it can be said that the K value is accurate. The result of calculating the patient with this K value is also accurate, so the K value is very critical.

4. The true face of K value

 The K value actually represents the slope, and the intercept represents the reagent blank. The reagent blank changes every day, so the stability of the K value determines your instrument and reagents. If the instrument and reagents are stable, the K value is also very stable.

5. How often is it appropriate to calibrate?

 This depends on the stability of your reagents. The quality control results are not good. Some items can be solved by reagent blanks, and some items require two-point calibration.

6. Can the biochemical analyzer be calibrated every day to ensure stable results?

Not necessarily, you may not re-dissolve the calibration solution every day during calibration, because some items are unstable after the calibration solution is reconstituted, such as: TBIL, DBIL (see light decomposition), GLU (bacterial decomposition), enzyme Items (reconstituted and degraded after freezing). Solution: When calibrating the above items, a new bottle of calibration solution must be dissolved for at least 30 minutes, and the measurement is completed within 1 hour.