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If the plasmids you wish to transform are very big (more than 20kb), the co-transformation might not be very efficient (you might not get any colonies). Electroporation should work though, as electrocompetent cells are more efficient than chemically competent cells. Alternatively, as you have read, you could transform your first plasmid and select for it, ...


5

See here. Histones are basic proteins (cationic, high pI) because they are required to interact with polyanionic DNA at physiological pH. Heparin and dextran are polyanions which form insoluble salts with the cationic histones.(Dextran is a polymer of glucose. In dextran sulphate it is derivatised with sulphonate groups creating a polyanionic material.) ...


5

No, it isn't that simple, because centrifugal force varies with the square of the rotor speed. Have a look at the Wikipedia page for clearing factor. Those equations are usually used to determine what you need to do if you are going to use a different rotor, but they can also be used to solve your question. Because you are looking at a situation where the ...


2

What you are asking about is the precipitation of DNA (or any other nucleic acid) by isopropanol (or ethanol, which is more common). To do so, you add salt (usually slightly acidic sodium acetate) which makes sure that the phosphate backbone of the DNA is saturated with sodium ions to make it less soluble. Then you add the organic solvent, which precipitates ...



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