You cannot reliably compare absolute FSC-A values between different days or different instruments unless you use standardized beads (e.g., Cytometer Setup and Tracking beads). Even then, FSC is highly sensitive to laser alignment, fluidics, and temperature. For quantitative size comparisons, use calibrated beads (e.g., SpheroTech) to convert FSC-A into microns.
The maximum intensity or peak of the signal. You cannot reliably compare absolute FSC-A values between
By plotting , single cells fall along a diagonal line (where Area ≈ Height × a constant). Doublets, however, show a high FSC-A but a normal FSC-H, causing them to fall above the diagonal. The maximum intensity or peak of the signal
One of the most critical steps in data analysis is ensuring you are looking at single cells (singlets), not two cells stuck together (doublets). By plotting FSC-A vs. FSC-H , you can identify doublets; single cells will fall along a diagonal line, while doublets (which have a larger area relative to their height) will shift off that line. One of the most critical steps in data
Older or simpler cytometers (like the first-generation Guava systems or some CytoFLEX configurations) may not report FSC-H or FSC-W. In these cases, you cannot perform traditional doublet discrimination. Alternatives include using or fluorescence pulse geometry (e.g., PI-A vs. PI-W in cell cycle).
FSC-A is generally proportional to the cross-sectional area of the cell. Scientists use it to differentiate cell types, such as separating small lymphocytes from larger monocytes or granulocytes in blood samples.