How to identify lanes on large agarose gels?

[Jose de las Heras]

"Peter Frank" <peter_frankde from yahoo.de> wrote in message 
news:jineb31948q6bnf5g6kegn0lbuaiuuam9t from 4ax.com...
> Hi,
>
> I ran a large agarose gels for analyzing PCR products. The gel has
> many narrow lanes. Problem is that there isn't a band in every lane,
> sometimes there are several empty lanes between bands, and this makes
> it difficult to identify the lanes because the wells are not visible
> on the gel picture. However, I need to be able to clearly identify the
> lanes so that I know where there is a PCR product and where there is
> none.
>
> Drawing equally sized lines to locate the lanes did not really work
> well because of the imperfection of the gel or gel run.
>
> Can you give me any tips on how to handle this problem? I was thinking
> of putting a marker lane onto the gel every 4 lanes so that there
> wouldn't be large spaces without anything. But I am not sure if this
> is the best solution (besides, it would cost me a lot of DNA marker).
>
> Peter

when a PCR gives you a band, you see it... when it doesn't, the primers 
don't get used up and you *may* be able to see them, depending on how much 
you use per reaction.

In cases like that, I just take two pictures of the gel, one to see the 
bands nicely, and another tweaking exposure/brightness so that i can see the 
wells, even if most bands appear overexposed... between the two I identify 
every single lane.

Jose