Cell fractionation
Encyclopedia
Cell fractionation is the separation of homogeneous sets, usually organelle
s, from a heterogeneous population of cells.
buffer solution using a variety of mechanisms. A 'Potter-Elvehjem homogeniser' is often used as it is relatively gentle. Other procedures include grinding, mincing, chopping, pressure changes, osmotic shock, freeze-thawing, and ultra-sound homogenization.
The solution is homogenized in an isotonic solution to stop osmotic damage, with a pH buffer to regulate pH, and at an ice-cold temperature to prevent enzyme damage. The organelles are kept either cold, isotonic or buffered.
See Cell disruption
for further details.
- the sequential increase in gravitational force resulting in the sequential separation of organelles according to their density.
Media for cell separation by density:
Organelle
In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer....
s, from a heterogeneous population of cells.
Steps
There are three principal steps involved:- Disruption (homogenization) of cells and liberation of organelles.
- Macro Filtration
- Purification of cell components.
Homogenization
Tissue is typically homogenized in an isotonicIsotonic
The term isotonic may refer to;*Isotonic for the term associated with muscle contraction*An isotone in nuclear physics*Sports drinks are sometimes designed in an isotonic way to assist athletes rehydrate while balancing electrolytes...
buffer solution using a variety of mechanisms. A 'Potter-Elvehjem homogeniser' is often used as it is relatively gentle. Other procedures include grinding, mincing, chopping, pressure changes, osmotic shock, freeze-thawing, and ultra-sound homogenization.
The solution is homogenized in an isotonic solution to stop osmotic damage, with a pH buffer to regulate pH, and at an ice-cold temperature to prevent enzyme damage. The organelles are kept either cold, isotonic or buffered.
See Cell disruption
Cell disruption
Cell disruption is a method or process for releasing biological molecules from inside a cell.- Choice of disruption method:The production of biologically-interesting molecules using cloning and culturing methods allows the study and manufacture of relevant molecules.Except for excreted molecules,...
for further details.
Filtration
This step may not be necessary depending on the source of the cells. Animal tissue however is likely to yield connective tissue which must be removed. Commonly, filtration is achieved either by pouring through gauze or with a suction filter and the relevant grade ceramic filter.Purification
Invariably achieved by Differential centrifugationDifferential centrifugation
Differential centrifugation is a common procedure in microbiology and cytology used to separate certain organelles from whole cells for further analysis of specific parts of cells. In the process, a tissue sample is first homogenised to break the cell membranes and mix up the cell contents...
- the sequential increase in gravitational force resulting in the sequential separation of organelles according to their density.
See also
- Cell disruptionCell disruptionCell disruption is a method or process for releasing biological molecules from inside a cell.- Choice of disruption method:The production of biologically-interesting molecules using cloning and culturing methods allows the study and manufacture of relevant molecules.Except for excreted molecules,...
- Differential centrifugationDifferential centrifugationDifferential centrifugation is a common procedure in microbiology and cytology used to separate certain organelles from whole cells for further analysis of specific parts of cells. In the process, a tissue sample is first homogenised to break the cell membranes and mix up the cell contents...
Media for cell separation by density:
- PercollPercollPercoll was first formulated by Pertoft et al. as a tool for more efficient density separation. It is used for the isolation of cells, organelles, and/or viruses by density centrifugation...
- FicollFicollFicoll is a neutral, highly branched, high-mass, hydrophilic polysaccharide which dissolves readily in aqueous solutions. Ficoll radii range from 2-7 nm. It is prepared by reaction of the polysaccharide with epichlorohydrin...
External links
- Microfluidicscorp - MFIC OTC
- Subcellular Fractionation Kit Review from Biocompare