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2-Phenylethyl bromide is an organobromide with the formula C 6 H 5 CH 2 CH 2 Br. It is a colorless liquid, although older samples appear yellow. Analogous to the preparation of most 1-bromoalkanes, it is prepared by free-radical addition of hydrogen bromide to styrene. These conditions lead to anti-Markovnikov addition, giving the 1-bromo ...
An old qualitative test for the presence of the alkene functional group is that alkenes turn brown aqueous bromine solutions colourless, forming a bromohydrin with some of the dibromoalkane also produced. The reaction passes through a short-lived strongly electrophilic bromonium intermediate. This is an example of a halogen addition reaction. [18]
Bromide ions, as provided by salts like sodium bromide, function as a nucleophiles in the formation of organobromine compounds by displacement. [4] An example of this salt mediated bromide displacement is the use of Copper(II) bromide on ketones: [5] [6] R-CO-CH 2-R' + 2 CuBr 2 → R-CO-CHBr-R' + 2 CuBr + HBr
In organic chemistry, the bromine test is a qualitative test for the presence of unsaturation (carbon-to-carbon double or triple bonds), phenols and anilines. An unknown sample is treated with a small amount of elemental bromine in an organic solvent, being as dichloromethane or carbon tetrachloride. Presence of unsaturation and/or phenol or ...
The chemicals used in most northern blots can be a risk to the researcher, since formaldehyde, radioactive material, ethidium bromide, DEPC, and UV light are all harmful under certain exposures. [11] Compared to RT-PCR, northern blotting has a low sensitivity, but it also has a high specificity, which is important to reduce false positive results.
Increasing ethidium bromide intercalated into the DNA can change it from a negatively supercoiled molecule into a fully relaxed form, then to positively coiled superhelix at maximum intercalation. [9] Agarose gel electrophoresis can be used to resolve circular DNA with different supercoiling topology.
For example, the positive charge of ethidium bromide can reduce the DNA movement by 15%. [12] Agarose gel electrophoresis can be used to resolve circular DNA with different supercoiling topology. [16] DNA damage due to increased cross-linking will also reduce electrophoretic DNA migration in a dose-dependent way. [17] [18]
Fresh normal plasma has all the blood coagulation factors with normal levels. If the problem is a simple factor deficiency, mixing the patient plasma 1:1 with plasma that contains 100% of the normal factor level results in a level ≥50% in the mixture (say the patient has an activity of 0%; the average of 100% + 0% = 50%). [3]