DICTIONARY - CELL STRUCTUREi

Plasma membrane


 Staining of plasma membrane in human cell line A-431 (HPA021616)
Scale bar represents 10µm

Plasma membrane

The plasma membrane consists of a lipid bilayer, which encloses the cell and protects it from its surroundings. It enables transport of molecules in and out of the cell either through passive diffusion or through active uptake. Additionally, it takes part in cellular processes including signal transduction through receptors embedded in the membrane.

Immunofluorescent staining

Immunofluorescent staining of the plasma membrane can appear in different ways. Sometimes the staining appears as a clear rim around the cell and sometimes membrane protrusions extending from the plasma membrane are visible. In other cases the staining can be uniform and flat across the entire cell (since the plasma membrane beneath the cell is stained). For those cases it can be difficult to distinguish between a staining of the plasma membrane and a cytoplasmic staining. A plasma membrane staining is usually easy to distinguish from a staining of the cell junctions, as the latter one is only visible at sites where cells are in contact with each other. However, if many cells are close to each other the distinction between plasma membrane and cell junctions gets more difficult.

Read more about the proteome of the plasma membrane.