I want to know why an assay with a Z' over 0.5 is defined as a "good assay".
The Z-factor is a measure of statisticaleffect size. It has been proposed for use in high-throughput screening to judge whether the response in a particular assay is large enough to warrant further attention.
Ideal. Z-factors can never exceed 1.
between 0.5 and 1.0
An excellent assay. Note that if σp = σn, 0.5 is equivalent to a separation of 12 standard deviations between μp and μn.
between 0 and 0.5
A marginal assay.
less than 0
There is too much overlap between the positive and negative controls for the assay to be useful.
check the following Refernces for more
thanks for your help!