cell culture

Examples of cell culture in the following topics:

• Tissue Culture of Animal Viruses

  • In practice, the term "cell culture" now refers to the culturing of cells derived from multi-cellular eukaryotes, especially animal cells.
  • The historical development and methods of cell culture are closely interrelated to those of tissue culture and organ culture.
  • Cultured cells, eggs, and laboratory animals may be used for virus isolation.
  • Cell cultures vary greatly in their susceptibility to different viruses.
  • Discover the use of, and reasons for, culturing animal viruses in host cells

• Batch Culture of Bacteriophages

  • Bacteriophage cultures require host cells in which the virus or phage multiply.
  • Virus or phage cultures require host cells in which to multiply.
  • For bacteriophages, cultures are grown by infecting bacterial cells .
  • Virus or phage cultures require host cells in which to multiply.
  • For bacteriophages, cultures are grown by infecting bacterial cells.

• Direct Counting

  • By counting the cells in a known volume of a culture, the concentration can be assessed.
  • In medicine, the concentration of various blood cells, such as red blood cells or white blood cells, can give crucial information regarding someone's health.
  • One can also quantify the number of cells in a culture by plating a known volume of the cell culture on a petri dish with a growth medium, which is also known as a streak plate.
  • The colonies can then be counted and, based on the known volume of the culture that was spread on the plate, the cell concentration can be calculated.
  • As with hemocytometers or counting chambers, cultures need to be heavily diluted prior to plating.

• Measurements of Microbial Mass

  • Cell cultures are turbid: they absorb some of the light and let the rest of it pass through.
  • In spectrophotometry, cultures usually do not need to be diluted, although above a certain cell density the results lose reliability.
  • This, combined with the stochastic nature of liquid cultures, enables only an estimation of cell numbers.
  • An additional method for the measurement of microbial mass is the quantification of cells in a culture by plating the cells on a petri dish.
  • The colonies can then be counted, and based on the known volume of culture that was spread on the plate the cell concentration can be calculated.

• Pure Culture

  • A pure culture is a population of cells or multicellular organisms growing in the absence of other species or types.
  • A pure (or axenic) culture is a population of cells or multicellular organisms growing in the absence of other species or types.
  • A pure culture may originate from a single cell or single organism, in which case the cells are genetic clones of one another.
  • Another method of bacterial culture is liquid culture, in which the desired bacteria are suspended in liquid broth, a nutrient medium.
  • Geomyces destructans in culture from bat tissues.

• Putting Foreign DNA into Cells

  • In mammalian cell culture, the analogous process of introducing DNA into cells is commonly termed transfection.
  • Both transformation and transfection usually require preparation of the cells through a special growth regime and chemical treatment process that will vary with the specific species and cell types that are used.
  • Electroporation uses high voltage electrical pulses to translocate DNA across the cell membrane (and cell wall, if present) .
  • When bacterial cells are used as host organisms, the selectable marker is usually a gene that confers resistance to an antibiotic that would otherwise kill the cells, typically ampicillin.
  • When mammalian cells (e.g., human or mouse cells) are used, a similar strategy is used, except that the marker gene (in this case typically encoded as part of the kanMX cassette) confers resistance to the antibiotic Geneticin.

• Caulobacter Differentiation

  • A Caulobacter is used for studying the regulation of the cell cycle, asymmetric cell division, and cellular differentiation.
  • Swarmer cells differentiate into stalked cells after a short period of motility.
  • Chromosome replication and cell division only occurs in the stalked cell stage.
  • The isolated swarmer cells can then be grown as a synchronized cell culture.
  • Swarmer cells differentiate into stalked cells after a short period of motility.

• Osmotic Pressure

  • The correct osmotic pressure in the culture medium is essential for the survival of the cells.
  • Osmotic pressure is an important factor that affects cells.
  • Having the correct osmotic pressure in the culture medium is essential.
  • A cell can be influenced by a solution in three ways.
  • If the medium is hypotonic — a diluted solution with a higher water concentration than the cell — the cell will gain water through osmosis .

• Tracking Cells with Light

  • Advanced technology enables tracking cells with light by introducing fluorescent or luminescent reporter genes into the cells' genome.
  • Cells undergo many dynamic processes.
  • In order to visualize these processes we need to be able to film cells over time.
  • Luciferase is similarly useful as a biological marker in living cells and organisms.
  • For bacteria or prokaryotic cells in culture, this is usually in the form of a circular DNA molecule called a plasmid .

• Generation Time

  • Providing no mutational event occurs the resulting daughter cells are genetically identical to the original cell.
  • The measurement of an exponential bacterial growth curve in batch culture was traditionally a part of the training of all microbiologists.
  • In autecological studies, bacterial growth in batch culture can be modeled with four different phases: lag phase, exponential or log phase, stationary phase, and death phase .
  • This basic batch culture growth model draws out and emphasizes aspects of bacterial growth which may differ from the growth of macrofauna.
  • In reality, even in batch culture, the four phases are not well defined.