I frequently perform an assay that results in multiple measurements for each of my samples. For example I may have four replicate control samples that were each measured three times and four replicate experimental samples that were measured three times each. I would like to know how to account for variability between the samples and the variability between the measurements of each replicate. Is there a way to express a single standard deviation that takes into account both of these.
Below is an example:
Untreated Control Group
Sample 1 - 3 Measurements 96% 103% 102%
Sample 2 - 3 Measurements 104% 90% 92%
Sample 3 - 3 Measurements 104% 104% 94%
Sample 4 - 3 Measurements 103% 107% 100%
Treated Experimental Group
Sample 1 - 3 Measurements 46% 48% 46%
Sample 2 - 3 Measurements 43% 54% 45%
Sample 3 - 3 Measurements 56% 52% 44%
Sample 4 - 3 Measurements 56% 59% 55%
Below is an example:
Untreated Control Group
Sample 1 - 3 Measurements 96% 103% 102%
Sample 2 - 3 Measurements 104% 90% 92%
Sample 3 - 3 Measurements 104% 104% 94%
Sample 4 - 3 Measurements 103% 107% 100%
Treated Experimental Group
Sample 1 - 3 Measurements 46% 48% 46%
Sample 2 - 3 Measurements 43% 54% 45%
Sample 3 - 3 Measurements 56% 52% 44%
Sample 4 - 3 Measurements 56% 59% 55%