Which characteristic is assessed using side scatter (SSC) in flow cytometry?

Side scatter (SSC) in flow cytometry primarily assesses cell granularity. This characteristic reflects the internal complexity of a cell, which often correlates with the presence of granules or the physical structures within the cytoplasm. Granular cells, such as neutrophils or mast cells, exhibit higher SSC values compared to non-granular cells, like lymphocytes.

Moreover, side scatter takes advantage of the laser-light scattering phenomenon; as the laser light passes through the cell, the internal structures scatter the light in various directions. The degree of this scattering is indicative of the cell's granularity. This measure is essential for distinguishing different types of cells based on their internal complexity, which is particularly valuable in areas like immunology and hematology.

While other options like cell shape, membrane integrity, and metabolic state are vital characteristics in cytometry, they are more accurately assessed through different parameters or techniques. Cell shape is more commonly evaluated through forward scatter (FSC), which measures the size and overall shape. Membrane integrity often requires specific dyes or assays, while metabolic state is usually determined using viability dyes or metabolic indicators that are not based solely on scatter properties.