standard curve replicates

[hariszaf]

Instead of having only blanks, in some spectrophotometry experiments people may also have some standard biomass so they know what they count; building something like a standardization curve?

For example, well_1 is a blank, while well_2 has 10^5 cells (known in advance).

Should we add an extra flag like for blanks to consider these cases?
@hallucigenia-sparsa