Can I put the Elisa standard curve in my master's thesis?

1. Several problems that should be paid attention to when detecting the standard curve samples of ELISA kit.

1, sample concentration and other indicators are calculated according to the standard curve, so it is more important to do the standard curve first than to do the formal experiment, otherwise the following experimental results will be impossible.

2. Set the standard concentration range of the standard curve sample to have a relatively large span, and cover the concentration of the experimental sample you want to test, that is, the concentration of the sample should be within the standard curve concentration range, including the upper and lower limits. For the S-shaped standard curve, try to make the concentration of the experimental sample in the steepest section in the middle, that is, the curve is almost straight.

3. The concentration of the standard sample in the standard curve is best prepared by multiple dilution method, and the ELISA kit can ensure that the concentration of the standard sample will not be greatly deviated.

4. When testing the standard sample, it should be carried out in the order of increasing concentration, so as to reduce the influence of high concentration on low concentration and improve the accuracy.

5. The sample number of standard curve is generally 7 points, but at least 5 points should be guaranteed.

6. The correlation coefficient of standard curve varies with different experimental requirements, but generally speaking, the correlation coefficient r should be at least greater than 0.98, and for some experiments, it should be at least 0.99 or even 0.999.

Second, choose what equation to fit.

Power equation can be well fitted in the low concentration section of S curve, linear equation can be used in the middle and low concentration section, logarithmic equation can be used in the middle section, and four parameters can be used in the middle and late stage. Calibration point in immunoassay (which can be multiple ratio)

Dilution, or no dilution) If the concentration and the corresponding absorbance (OD) value can present a linear relationship, it is of course the most ideal. At this time, the fitting curve can be easily obtained by EXELL and others, and then calculated.

The concentration value of the sample.

As for the fitting methods of calibration curves, although straight lines, quadratic curves, cubic curves, exponents and logarithms can all be used for curve fitting in biological reactions such as ELISA, they are all used for only a part of curves, some for the first half, some for the second half and some for the middle part, and Logistic curves are all applicable.

In a long time interval, the logic should be able to fit perfectly. If it is used for quantization, the middle section (steep part) of S-shaped curve is better, while the calculation error of two real flat parts will be larger, sometimes

It will even be big. The so-called "calibration curve" for immunoassay is actually called fitting curve. At present, the most popular fitting method of immunoassay in the world is "four-parameter logical fitting", which can often

It can accurately reflect the curve relationship between concentration and absorbance, so as to further accurately obtain the concentration value of the substance to be measured in the sample. But when we do immunoassay, we seldom have such an ideal situation, the concentration of the standard.

However, the corresponding OD value is often an "S" curve. At this time, the straight line fitting method cannot be used, and the fitting method needs to be selected. The key is which part of your calibration curve is S-shaped.

Which part of the curve is the concentration of the sample you want to test? Of course, if it is used for quantification, it is better to put it in the middle section. But it is one thing to build a model, and it is another to quantify it with ELISA kit. These methods are reliable.

However, no method can be universally applied, but all of them can be used. But it doesn't mean that it is omnipotent. In fact, not only ELISA, but also many other biological reactions are S-shaped curves, which can also be fitted by Logistic curves.