Schematic of a flow cytometer. The laser interacts with the cell in the quartz flow cell. Three ...

Schematic of a flow cytometer. The laser interacts with the cell in the quartz flow cell. Three things happen after the light hits a cell: (1) Some of the light is scattered forward due to the size of the cell and is measured by the forward scatter (FS) photodiode (2) some of the light is scattered due to the granularity of the cell and is measured by the side scatter photomultiplier tube (SS PMT), and (3) the laser light excites the fluorochromes attached to the cell and light emitted from the fluorochrome is measured. The fluorescent light (FL) that is yellowish-orange is measured in the FL2 PMT, and the green light is measured in FL1 PMT.