no DNA band - (Feb/07/2007 )
i really have trouble getting dna bands on my gel. i tried twice but with no results. why does it happen? i was sure that all my stuff were ok. is there anything else that i have to check on?
Tell us which stuff do you think are ok? Is there a chance that they might not be ok? Do you use EtBr or something else? How much EtBr are you using? What is the amount of DNA you are loading in your gels? How long is the DNA? What is the percentage of the gel?
Did you spec ur DNA, if not trying doing it, u will know if the DNA concentration u r loading is too less.
Quantify first to check is there anything. Can't really help because I don't really understand the situation.
If DNA marker is there but your DNA is NOT, my guess is your sample problem
is it genomic DNA prep or a plasmid? Try to run it for about 10 min in 0.8% Agarose on 1xTAE and if u see bands quantify the DNA. WHat protocol are u following? is it CTAB based method or any other method? You really have to standardise the protocol to ur need if u are trying to extract DNA from an organism or plant if available protocols do not work. i too faced similar problems and iam now using Silica based columns for extracion.
If u could tell ur exact organism i can help.