Biotek PowerWave Operator's Manual page 54

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| Chapter 4: Instrument Qualification
Calculate the results for Repeatability:
4.
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Channel-to-Channel Variation and Alignment
Using the plate prepared for the tests above, conduct a turnaround test by
1.
reading the plate with the A1 well in the H12 position five times. This test
results in four comparisons of each channel to its corresponding channel,
two in column 1, and two in column 2.
Calculate the means of the wells in columns 1 and 2 in the normal plate
2.
position (data is from the tests above) and in the turnaround position (from
Step 1 above). Compare the mean reading for well A1 to its mean reading
when in the H12 position.
Compare the mean values for the other wells to their corresponding mean
3.
values with the well in the turnaround position. (Compare B1 to G12, C1 to
F12, D1 to E12, E1 to D12, F1 to C12, G1 to B12, H1 to A12, A2 to H11, and
B2 to G11, etc.). The difference in the values for any two corresponding
wells should be within the accuracy specification for the instrument.
For example: If the mean of well A1 in the normal position is 1.902, where
the specified accuracy is ± 1.0% ± 0.010 OD, then the expected range for the
mean of the same well in the H12 position is 1.873 to 1.931 OD. (1.902 * 1% =
0.019 + 0.010 = 0.029, which is added and subtracted from 1.902 for the
range.)
Since it is somewhat difficult to achieve high pipetting accuracy when
conducting linear dilutions, an R Square value of at least 0.99 is
considered adequate.
Calculate the mean and standard deviation for the five readings taken in
Step 1 at each concentration. Only one row of data needs to be analyzed.
For each mean below 2.000 OD, calculate the allowed deviation using
the repeatability specification for a 96-well plate of ± 1.0% ± 0.005 OD. If
above 2.000 OD, apply the ± 3.0% ± 0.005 specification.
The standard deviation for each set of readings should be less than the
allowed deviation.
Absorbance readings of 1.950, 1.948, 1.955, 1.952, and 1.950
Example:
will result in a mean of 1.951, and a standard deviation of 0.0026. The
mean (1.951) multiplied by 1% (1.951 * 0.010) = 0.0195, which, when
added to the 0.005 (0.0195 + 0.005) = 0.0245 OD, which is the allowable
deviation. Since the standard deviation is less than this value, the reader
meets the test criteria.
Repeatability Specification:
± 1% ± 0.005 OD from 0.000 OD to 2.000 OD
± 3% ± 0.005 OD from 2.000 OD to 3.000 OD
BioTek Instruments, Inc.