Sejttömeg

Sejttömeg, or cell mass, denotes the total mass of a single biological cell. It includes water, cytoplasm, organelles, and all macromolecules such as proteins, nucleic acids, lipids, and metabolites. Across cell types, sejttömeg spans a broad range, typically from the low picograms to the low nanograms per cell, depending on species, tissue type, and physiological state. Water usually makes up the largest portion of the total mass, while the dry mass reflects the cell’s macromolecular content.

Measuring sejttömeg is challenging at the single-cell level. Direct gravimetric weighing is impractical for individual cells, so scientists infer mass from related properties. Common approaches include optical methods such as quantitative phase imaging, which links phase shifts to the dry mass; buoyant mass measurements using microbalance technologies; and estimations from cell volume obtained by microscopy or flow cytometry combined with an assumed density. When mass is inferred from volume, a density assumption is required, and results can vary with hydration level and intracellular composition.

The sejttömeg of a cell changes during growth and the cell cycle, and it is linked to metabolic rate, protein synthesis, and overall cellular physiology. In research and medicine, tracking cell mass helps study growth dynamics, responses to drugs, and disease states such as cancer, where altered growth and mass accumulation are common. Measurements rely on complementary methods and appropriate calibrations to ensure accuracy.