Immunofluorescent images of formaldehyde-fixed cell lines are shown. Three different organelle markers are displayed as different channels in the multicolor images - nucleus stained in blue, microtubules in red and ER in yellow. The various cell structures that are demonstrated are always shown in the green channel using an antibody found in the Human Protein Atlas. The antibody id is linked to the corresponding Cell Atlas protein page. By using the "toggle channels"-buttons, the different channels can be turned on and off. Most cell structures can be highlighted in the cell illustration by hovering over them with the exception of the aggresome. Cytoplasmic bodies are highlighted as cytosol; cytokinetic bridge, midbody, midbody ring and mitotic spindle are highlighted as microtubules, cell junctions are highlighted as plasma membrane and nucleus is highlighted as nucleoplasm.
Staining of plasma membrane in human cell line U-251 MG (HPA031345)
Scale bar represents 10µm
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 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.