# Comparison Between Elisa and Rio

Topics: Analytic geometry, Normal distribution, ELISA Pages: 2 (499 words) Published: April 6, 2013
Comparison between ELISA and RIA tubes

Introduction:
The main objective of this study is to compare the treatment of ELISA results and RIA results. Radioimmunoassay (RIA) is a very sensitive in vitro assay technique used to measure concentrations of antigens by use of antibodies. An alternate method to RIA is ELISA, where the antigen-antibody reaction is measured using colorimetric signals instead of a radioactive signal. The data from the RIA will have been processed by the gamma counter onboard software and counts per minute (CPMs) will have been converted to concentrations. The ELISA data contains absorbances (optical densities) from our ELISA microtitre plate. Methods:

For ELISA data, the standard normal curve is constructed by taking the Log10 concentration of standard progesterone along x axis and mean absorbance estimated from ELISA data on Y axis. This curve then can be used to determine the concentration values of ELISA (pg/100uL). Initially, the standard curve is drawn by taking all the 10 values and the second standard curve was constructed by eliminating the outliers. The equation from the standard curve that contributes to the best fit straight line was taken into consideration. The concentration values of ELISA (pg/100uL) was then calculated by using the formula

Where
Y = Log10 of concentration
X = absorbance
c = the point the slope crosses the Y-axis
On substituting various Y values, we obtain the logarithmic values of absorbance. It is then converted into real value by using the relation 10A

Results:
The standard curve constructed between concentration of standard progesterone (x axis) and mean absorbance estimated from ELISA data (Y axis) is given below:

From the above standard curve, we see that there exists a very strong negative linear relationship between ELISA and RIA results. The correlation of the ELISA results with RIA was good (r = - 0.9203). The best fit straight line is given by: Y = -...