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Typically, a glycerol stock will have a final concentration of 10-20% of glycerol. Glycerol is highly viscous. Pipetting higher concentrations of glycerol is difficult (especially for smaller volumes). Therefore a lower concentration such as a 50% solution (works for me) is convenient: add 300µl to 700µl of bacterial culture. Regarding 87%: some vendors ...


3

The context for identifying E. coli is primarily clinical Microbiology, and in the clinical lab the identification is primarily phenotypic, based on various properties such as growth and morphology on selective media, Gram stain appearance, biochemical characteristics, etc - only under unusual circumstances is genetic testing done. The latter is problematic ...


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Yes. This has been possible since the 1990's. In the US recently, the flu vaccine was recently offered as a nasal spray. There is current research being done to aerosolize several vaccines. Public health officials have an interest in this method due to it being less expensive to produce, more people can receive the vaccine in a shorter time frame, and less ...


2

The double-stranded DNA fragments are fractionated by size during the agarose gel electrophoresis. Prior to the so-called “blotting” step, the gel is briefly soaked in a solution of NaOH, which has a relatively high pH. Under these conditions, double-stranded DNA will denature, or “melt” into two single strands. This is the material that is “wicked” or “...


1

Via: https://en.wikipedia.org/wiki/Carbon-13#Uses_in_science Due to differential uptake in plants as well as marine carbonates of 13C, it is possible to use these isotopic signatures in earth science. Biological processes preferentially take up the lower mass isotope through kinetic fractionation. Via: https://en.wikipedia.org/wiki/Kinetic_fractionation ...


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