Serial dilution examples. Serial dilutions are a common practice in the natural sciences. Due to the period decrease in concentration, this method is very useful when performing many types of experiments, from chemistry to biology to medicine. To perform a serial dilution, a small amount of a well-mixed solution is transferred into a new container and additional water or other solvent. is added to dilute the original solution. The diluted sample is then used as the base solution to make an additional dilution. Doing this several times results in a range of concentrations. Serial Dilution Calculations. Separate Calculations for Each Step. If there are only a few serial dilutions, the calculations can be done separately for each step. For example, let's say you needed 3 standard solutions for an experiment, and you were given a stock solution with a concentration of 5.0 ppm. Jun 17, 2014 A serial dilution is any dilution in which the concentration decreases by the same factor in each successive step. In serial dilutions, you multiply the dilution factors for each step. The dilution factor or the dilution is the initial volume divided by the final volume. #DF = Vi/Vf# For example, if you add a 1 mL sample to 9 mL of diluent to get 10 mL of solution. A dilution is a reduction in the concentration of a solution. A serial dilution is a series of repeated dilutions that provides a geometric dilution of the original solution. This is commonly performed in experiments that involve concentration curves on a logarithmic scale. Serial dilutions are used extensively in biochemistry and microbiology. The solution dilution calculator tool calculates the volume of stock concentrate to add to achieve a specified volume and concentration. The calculator uses the formula M 1 V 1 = M 2 V 2 where '1' represents the concentrated conditions (i.e. Stock solution Molarity and volume) and '2' represents the diluted conditions (i.e. Desired volume.
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]
See also[edit]
References[edit]
- ^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.
Two Fold Serial Dilution
- Michael L. Bishop, Edward P. Fody, Larry E. Schoeff. Clinical Chemistry: Principles, Procedures, Correlations. Lippincott Williams & Wilkins, 2004, p. 24. ISBN0-7817-4611-6.
Serial Dilution Calculation Examples
External links[edit]
- How to Make Simple Solutions and Dilutions, Bates College
How To Make Dilution Series
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