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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[edit]
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[edit]
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]
- 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.
- Advantage - it has countable viable cells to count Disadvantage - spread and pour plates might not always have a single colony that represents the progeny of a single cell What is the advantages and disadvantages to the serial dilution agar plate procedure.
- Best Answer: you'd use serial dilution when you're pipeting a small amount. For example, pipetting 1 uL of anything is difficult since the amount is so small. If you've done it before you'll realize that 1 uL is a tiny drop that adheres to the walls of the pipet tip. This is when you'd want to use a serial dilution.
See also[edit]
References[edit]
The three 5.00 to 50.0 dilution steps shows not only an improvement of about half the measurement uncertainty of the 1000-fold dilution, it also saves approximately 75% of the solvent. There is no advantage in using three 10.00 to 100.0 dilution steps over three 5.00 to 50.0 dilution and it uses twice as much solvent.
- ^K. R. Aneja. Experiments in Microbiology, Plant Pathology and Biotechnology. New Age Publishers, 2005, p. 69. ISBN81-224-1494-X
- ^Booth, C.; et al. (2006). Extremophiles. Methods in microbiology 35. Academic Press. p. 543. ISBN978-0-12-521536-7.
- ^Weissmann, Gerald (2006). 'Homeopathy: Holmes, Hogwarts, and the Prince of Wales'. The FASEB Journal. 20 (11): 1755–1758. doi:10.1096/fj.06-0901ufm. PMID16940145. Retrieved 2008-02-01.
- ^Ernst, Edzard (November 2005). 'Is homeopathy a clinically valuable approach?'. Trends in Pharmacological Sciences. 26 (11): 547–548. CiteSeerX10.1.1.385.5505. doi:10.1016/j.tips.2005.09.003. PMID16165225.
- Michael L. Bishop, Edward P. Fody, Larry E. Schoeff. Clinical Chemistry: Principles, Procedures, Correlations. Lippincott Williams & Wilkins, 2004, p. 24. ISBN0-7817-4611-6.
External links[edit]
Disadvantages Of Serial Dilution
- How to Make Simple Solutions and Dilutions, Bates College