Molecular Devices SpectraMax Paradigm User Manual page 182

SpectraMax Paradigm Multi-Mode Detection Platform User Guide
W
Well Scan
A Well Scan read can take readings at more than one location within a well. A Well Scan read
takes one or more readings of a single well of a microplate on an evenly spaced grid inside of
each well at single or multiple wavelengths.
Some applications involve the detection of whole cells in large-area tissue culture plates. Well
Scan reads can be used with such microplates to permit maximum surface area detection in
whole-cell protocols. Since many cell lines tend to grow as clumps or in the corners of
microplate wells, you can choose from several patterns and define the number of points to
be scanned to work best with your particular application.
See Well Scan Read Type on page
Z
Z´
Z´ is the standard statistical parameter in the high-throughput screening community for
measuring the quality of a screening assay independent of test compounds. It is used as a
measure of the signal separation between the positive controls and the negative controls in
an assay.
The value of Z´ can be determined using the following formula:
Z´ = 1 –
where SD is the standard deviation, c+ is the positive control, and c– is the negative control.
A Z´ value greater than or equal to 0.4 is the generally acceptable minimum for an assay.
Higher values might be desired when results are more critical.
Z´ is not linear and can be made unrealistically small by outliers that skew the standard
deviations in either population. To improve the Z´ value, you can increase the quantity of
label in the sample, if acceptable for the assay, or increase the read time per well.
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21.
3(SD ) + 3(SD )
c+ c–
| Mean – Mean |
c+ c–
5014038 E