Technical Tip: Transferring quantitative data from ADAP to MS Excel Version 2.0
4
11.
Next, compile a table of the blank corrected absorbance values of the standards:
Well
Label
Compound
X
(
g/mL)
1
2
3
4
Mean
(OD)
Standard
Deviation
(OD)
Coefficient
of
Variation
(%)
S1
100.00
1.364
1.357
1.309
1.343
1.343
0.030
2.23%
S2
50
0.640
0.631
0.625
0.526
0.632
0.008
1.19%
S3
25.00
0.342
0.343
0.331
0.297
0.339
0.007
1.97%
S4
12.50
0.150
0.145
0.146
0.128
0.147
0.003
1.80%
S5
6.25
0.057
0.056
0.059
0.067
0.057
0.002
2.66%
S6
3.13
0.020
0.026
0.026
0.019
0.024
0.003
14.43%
S7
1.56
0.007
0.061
0.010
0.008
0.026
0.030
116.72%
For each standard, calculate the mean or average value, standard deviation and coefficient of variation
using the following formulas in Excel:
Mean Standard 1 (S1): =AVERAGE(wells A1, A2, A3 and A4)
Standard Deviation S1: =STDEV(wells A1, A2, A3 and A4)
Coefficient of Variation (%CV) =standard deviation/mean*100%
The %CV is a useful metric for determining the reliability of the data. Typically, %CV of <5% suggests
that the data is reliable (this assumption is assay type dependent). Thus the mean absorbance values
of S6 and S7 will not be included in the standard curve because the %CV is >5% (14.4% and 116.7%
respectively).
12.
Plot the mean absorbance values of standards S1 – S5 as a function of the known concentrations as a
x-y scatter plot:
Fit a linear regression trend line to the data by selecting trend line in the chart layout menu. The
example data conforms to the linear trend as represented by the R
2
value: 0.9989 or 99.89%.Thus the
equation of the linear regression trend line can be used to determine the concentration of samples
y = 0.0136x - 0.0231
R² = 0.9989
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
0.00
20.00
40.00
60.00
80.00
100.00
A
b
sor
b
an
ce
@
450 n
m
Concentration (ug/mL)
Absorbance vs Concentration of Compound X
Compound X
Linear
(Compound X)
