ı have really interesting problem.ı digested my plasmid DNA(2.5ug).To control digestion ı loaded 5 ul rxn mixture into well and ı see an excellent band.After checkıng dıgestıon ı dephosphorylated plasmıd DNA and loaded all mıxture into another weel but ı could not see any band 🙁 ı could not understand reason.any idea? please
You need to purify your DNA prior to running your gel. Salts and other impurities can interfere with the electrophoresis.
😯 Never heard that. I use electrophoresis to purify DNA…
As for the original question. Besides contamination of reagents by DNAse (it happened to someone I knew), there is no reason the DNA should disappear. The question is how much DNA in "all the mixture"? And did you had a purification step between the digestion and the dephosphorylation. If something went wrong at that step, that might explain your problems