Can you provide the general basis of the assay kits and how to calculate concentrations from the standard curve and sample data?
First, you need to built a standard curve, ” Plot the standard curve on log-log graph paper or using Sigma plot software, with standard concentration on the x-axis and absorbance on the y-axis. Draw the best-fit straight line through the standard points.” This standard curve is a formula, after you test your sample and get an absorbance value, the concentration could be calculated through the formula. one point could be noticed that the standard curve should be used for only one set of detection, different collect bathes should use a new curve. You can find the article here: http://img.creative-diagnostics.com/pdf/DEIA5268,CA19-9%20.pdf … more information: http://www.creative-diagnostics.com/ELISA-Kits.htm
A1. Most of Biovision’s sample assays show a Beer’s law (quasi-linear) relationship between the amount of analyte and either a colorimetric response (absorbance) or a fluorimetric response (RFU; relative fluorescence units). Hence the concentrations are derived using a linear regression equation obtained by fitting a trendline in Excel (ask Excel to show the equation and the R2 on the graph-but do not ask it to set the y-intercept at zero). The R2 value is a measure of how well the data can be fit by a straight line (good fits are ~ 0.99 and less than 0.98 is considered unacceptable). The linear equation is y = mx + b; where y = absorbance or RFU, x = sample amount, m = slope and b = y-intercept (the value at x = 0). One plots the standards after correcting for the reagent blank (i.e., 0 standard). The sample values must also be corrected for the reagent blank. In some cases, a sample background correction is also required. For example, in the triglyceride assay the triglycerides are c
