Use this calculation for cell-culture or microscopy observations collected with one counting rule, assay gate, calibration, and unit convention. It is suited to documenting dilution, growth, labeling, geometry, or population fractions.

Initial fluorescence

A finite measured or assumed value.

Current fluorescence

A finite measured or assumed value.

The implementation follows this calculation rule: Estimate cell division count from CFSE fluorescence dilution using the base two logarithm of the initial over current intensity.

Division count

The calculated division count.

Counts and fluorescence measurements can be biased by clumping, debris, segmentation, gating, background signal, saturation, sampling fields, or unequal viability. A calculated percentage does not identify the biological mechanism behind a change. The output is explicitly an estimate or proxy; preserve that label when reporting it.

Retain representative images or cytometry plots and include biological replicates. Orthogonal viability, proliferation, apoptosis, or direct counting assays can distinguish effects that a single cell metric conflates.

• CFSE MFI Halving

  Infer the number of CFSE fluorescence halvings, and hence cell generations, from parent and current mean fluorescence intensities.

• Doubling Time (PDT)

  Calculate population doubling time as elapsed hours times ln(2), divided by ln(final count / initial count).

• S Phase Fraction

  Compute the fraction of cells in S phase relative to the total counted cell population.