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A serial dilution is the step-wise dilution of a substance in solution, either by using a constant dilution factor, or by using a variable factor between dilutions. If the dilution factor at each step is constant, this results in a geometric progression of the concentration in a logarithmic fashion.
Commercially prepared enzyme-catalyzed solutions are inverted at 60 °C (140 °F). The optimum pH for inversion is 5.0. Invertase is added at a rate of about 0.15% of the syrup's weight, and inversion time will be about 8 hours. When completed the syrup temperature is raised to inactivate the invertase, but the syrup is concentrated in a vacuum ...
A typical protein in bacteria, such as E. coli, may have about 60 copies, and the volume of a bacterium is about 10 −15 L. Thus, the number concentration C is C = 60 / (10 −15 L) = 6 × 10 16 L −1. The molar concentration is c = C / N A = 6 × 10 16 L −1 / 6 × 10 23 mol −1 = 10 −7 mol/L = 100 nmol/L.
Dakin's original solution contained sodium hypochlorite (0.4% to 0.5%), prepared by treating calcium hypochlorite with sodium carbonate ("washing soda"). The solution left after removal of the insoluble calcium carbonate still contained some soda. [7] Boric acid (4%) was then added as a buffering agent to maintain a pH of between 9 and 10
In adult humans, there is about 18 g (0.63 oz) of glucose, [71] of which about 4 g (0.14 oz) is present in the blood. [72] Approximately 180–220 g (6.3–7.8 oz) of glucose is produced in the liver of an adult in 24 hours.
A 1:20 solution is isotonic with body fluids. 1:4 dilution is used for wound management applications; this contains 0.25% (w/v) available chlorine and has a pH of 10.5–11.2. [1] [2] The fluid has been used in endodontics, for example to irrigate an infected root canal, although it is not medically licensed for use in the mouth. [3]
Saline solution for irrigation. Normal saline (NSS, NS or N/S) is the commonly used phrase for a solution of 0.90% w/v of NaCl, 308 mOsm/L or 9.0 g per liter. Less commonly, this solution is referred to as physiological saline or isotonic saline (because it is approximately isotonic to blood serum, which makes it a physiologically normal solution).
Upon standing for 12 to 24 hours, fresh milk has a tendency to separate into a high-fat cream layer on top of a larger, low-fat milk layer. The cream often is sold as a separate product with its own uses. Today the separation of the cream from the milk usually is accomplished rapidly in centrifugal cream separators. The fat globules rise to the ...