Pengguna:Sscautm/Pencairan Bersiri
Pencairan bersiri adalah pencairan mengikut langkah demi langkah untuk sesuatu bahan dalam larutan. Kebiasaannya, kadar pencairan pada setiap langkah adalah konsisten, menghasilkan kepekatan "geometric progression" dalam bentuk logarithm. Sepuluh kali ganda pencairan bersiri contohnya, 1 M, 0.1 M, 0.01 M, 0.001 M.... Pencairan bersiri lazimnya digunakan untuk menghasilkan pencairan larutan yang tepat serta digunakan untuk eksperimen. 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[sunting | sunting sumber]
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[sunting | sunting sumber]
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]
References[sunting | sunting sumber]
- ^ K. R. Aneja.
- ^ Booth, C.; dll. (2006). Extremophiles. Methods in microbiology 35. Academic Press. m/s. 543. ISBN 0-12-521536-3. Cite has empty unknown parameters:
|chapterurl=dan|origdate=(bantuan) - ^ 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. Dicapai pada 2008-02-01.
- ^ Ernst, Edzard (November 2005). "Is homeopathy a clinically valuable approach?". Trends in Pharmacological Sciences. 26 (11): 547–548. doi:10.1016/j.tips.2005.09.003. PMID 16165225.
[[Kategori:Teknik makmal]]