Normalize Plates (POC)

Groups of data (e.g. wells of a plates) are normalized relative to a subset (e.g. some wells within that plate, e.g. negative control). For each group the mean (or median) is calculated for the selected subset. Based on this estimate, all data points of each group are normalized by applying this formula:

x.poc = x / mean(x[subset]) * 100
or
x.poc = x / median(x[subset]) * 100

Literature: Malo et al., Nat. Biotechnol. 24, 167-179 (2006)