The aggregation of fluorescently tagged
antibodies
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that caus ...
that are associated with proteins on
membranes
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. B ...
of living
cells
Cell most often refers to:
* Cell (biology), the functional basic unit of life
* Cellphone, a phone connected to a cellular network
* Clandestine cell, a penetration-resistant form of a secret or outlawed organization
* Electrochemical cell, a d ...
. The aggregation appears as a cap or a patch in the fluorescence microscope and is due to the bivalent nature of antibodies. Patching and capping were critical in demonstrating the fluid nature of plasma membranes.
Variations in density within the specimen are amplified to enhance contrast in unstained cells which is especially useful for examining living unpigmented cells. In other words, phase contrast is a contrast-enhancing optical technique that can be used to produce high contrast images such as living cells and subcellular including nuclei and other organelles. One of the major advantages of using phase contrast microscopy is that living cells can be examined in their natural state without being killed, fixed, or especially stained. As a result, biological processes in the cell can be observed and recorded in high contrast with sharp clarity of minute specimen details.
When the ligand binds to its specific receptor, the
ligand
In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's el ...
-
receptor
Receptor may refer to:
* Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse
*Receptor (biochemistry), in biochemistry, a protein molecule that receives and respond ...
complex accumulates in the coated pits. In many cells these pits and complexes begin to concentrate in one area of a cell. Cytochemically, this appears as patches of label on the cell surface (patching). Eventually, the patches coalesce to form a cap at one pole of the cell (capping). Not all cells form caps, but most do form patches. The pre-concentration process minimizes the amount of fluid that is taken up in the
vesicle
Vesicle may refer to:
; In cellular biology or chemistry
* Vesicle (biology and chemistry), a supramolecular assembly of lipid molecules, like a cell membrane
* Synaptic vesicle
; In human embryology
* Vesicle (embryology), bulge-like features ...
.
See also
*
Immunofluorescence
Immunofluorescence (IF) is a light microscopy-based technique that allows detection and localization of a wide variety of target biomolecules within a cell or tissue at a quantitative level. The technique utilizes the binding specificity of anti ...
References
Patching and Capping: Plasma Membrane Protein RedistributionPatching and Capping: Plasma Membrane Protein Redistribution
External links
Patching and Capping at "How to make humans"
{{DEFAULTSORT:Patching And Capping
Cell biology