Maria Feoktistova
= Maria Feoktistova
{c}
\b[Maria Feoktistova] is first author of a 2016 <crystal violet> staining protocol with <Peter Geserick> and <Martin Leverkus>. It quantifies material remaining attached to a culture surface, using a dye that binds cellular <proteins> and <DNA>.<Crystal Violet Assay for Determining Viability of Cultured Cells by Maria Feoktistova and others>[2016, byline and Abstract, maintained adherence and dye binding]{ref} The contribution concerns an experimentally accessible readout of changes in <cell culture>, rather than an intrinsic molecular count of viable <cells>.
A <crystal violet biomass response> becomes a cell-number estimate only through a suitable calibration. In an original matched-condition model, let
$$
A=0.050+0.040\frac{N}{1000},
$$
where $A$ is <absorbance> and $N$ the retained <cell> number. Standards containing 0, 2000 and 4000 <cells> give readings $0.050$, $0.130$ and $0.210$. A sample reading $0.250$ would imply $N=5000$ under this model.
The slope incorporates stain retained per <cell>, extraction and optical geometry. If a treatment doubles that per-cell response while preserving the background, only 2500 retained <cells> produce the same sample reading. An accurate measurement of colour can therefore coexist with an inaccurate biological interpretation. Independent counting and a calibrated response range test assumptions that repeated optical readings alone cannot settle. The numerical standards here are illustrative, not measurements from Feoktistova's protocol.