Serial dilution

A serial dilution is the stepwise dilution of a substance in solution. Usually the dilution factor at each step is constant, resulting in a geometric progression of the concentration in a logarithmic fashion. A ten-fold serial dilution could be 1 M, 0.1 M, 0.01 M, 0.001 M ... Serial dilutions are used to accurately create highly diluted solutions as well as solutions for experiments resulting in concentration curves with a logarithmic scale. A tenfold dilution for each step is called a logarithmic dilution or log-dilution, a 3.16-fold (100.5-fold) dilution is called a half-logarithmic dilution or half-log dilution, and a 1.78-fold (100.25-fold) dilution is called a quarter-logarithmic dilution or quarter-log dilution. Serial dilutions are widely used in experimental sciences, including biochemistry, pharmacology, microbiology, and physics.

In biology and medicine

In biology and medicine, besides the more conventional uses described above, serial dilution may also be used to reduce the concentration of microscopic organisms or cells in a sample. As, for instance, the number and size of bacterial colonies that grow on an agar plate in a given time is concentration-dependent, and since many other diagnostic techniques involve physically counting the number of micro-organisms or cells on specials printed with grids (for comparing concentrations of two organisms or cell types in the sample) or wells of a given volume (for absolute concentrations), dilution can be useful for getting more manageable results.[1] Serial dilution is also a cheaper and simpler method for preparing cultures from a single cell than optical tweezers and micromanipulators.[2]

In homeopathy
Main articles: Homeopathy and Homeopathic dilutions

Serial dilution is one of the core foundational practices of homeopathy, with "succussion", or shaking, occurring between each dilution. In homeopathy, serial dilutions (called potentisation) are often taken so far that by the time the last dilution is completed, no molecules of the original substance are likely to remain.[3][4]

gollark: But there are a lot of CC "Linux" "clones", so yes.
gollark: I would expect that more people have interacted with macOS than Linux.
gollark: Wild theory on new people constantly wanting to make an OS: they think something like "Oh wow, CC is so unlike Windows! And I have never seen any desktop OS but Windows! I must make it more like Windows so it is more familiar. Clearly nobody else has done this, or it would already be the default, because this is obviously better." Not explicitly/exactly that obviously, but think this might be close to what's going on.
gollark: You know what, I'll just drop support for any foolish people on old versions.
gollark: Stupid dan200ing dan200...

See also

References
  1. K. R. Aneja. Experiments in Microbiology, Plant Pathology and Biotechnology. New Age Publishers, 2005, p. 69. ISBN 81-224-1494-X
  2. Booth, C.; et al. (2006). Extremophiles. Methods in microbiology 35. Academic Press. p. 543. ISBN 978-0-12-521536-7.
  3. Weissmann, Gerald (2006). "Homeopathy: Holmes, Hogwarts, and the Prince of Wales". The FASEB Journal. 20 (11): 1755–1758. doi:10.1096/fj.06-0901ufm. PMID 16940145. Retrieved 2008-02-01.
  4. Ernst, Edzard (November 2005). "Is homeopathy a clinically valuable approach?". Trends in Pharmacological Sciences. 26 (11): 547–548. CiteSeerX 10.1.1.385.5505. doi:10.1016/j.tips.2005.09.003. PMID 16165225.
  • Michael L. Bishop, Edward P. Fody, Larry E. Schoeff. Clinical Chemistry: Principles, Procedures, Correlations. Lippincott Williams & Wilkins, 2004, p. 24. ISBN 0-7817-4611-6.
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