I saw this in a paper and I wanna do the same, but I don't know how much i have to add of DNA and EtBr:
A solution of linear calf thymus DNA (10 µg/mL) in the appropriate buffer was mixed with ethidium bromide (EtBr) in molar ratio EtBr/DNA phosphate of 1:20, corresponding to one molecule of intercalated EtBr per every 10th base pair.
HELP PLEASE! Thanks!