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.

Surface area

A finite measured or assumed value, expressed in µm².

The implementation follows this calculation rule: Derive the diameter of a spherical cell from its surface area in square micrometers.^[1]

Diameter

The calculated diameter in µm.

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. Preserve the input values and units so the result can be audited and recalculated.

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.

• Cell Surface Area Sphere

  Compute the surface area of a spherical cell from its radius in micrometers.

• Seeding Density

  Compute cell seeding density in cells per square centimeter from a cell count and growth area.

• Confluence %

  Compute the percentage of a culture vessel surface covered by cells from occupied and total flask areas.