ETBr in Loading Buffer

Gerd Nilsen gerdn at
Mon Feb 11 06:47:33 EST 2002

Works fine for DNA fragments of some size*. 

Just remember to put some in the ladder too.

Benefit: beutiful pictures
Drawback: might be diff. getting equal amount in each sample ->
comparing amounts of DNA more inaccurate
And, yes EtBr interferes with DNA movement in gel, but there should be
no difference between adding the EtBr in the gel or in the loading.
Staining the gel after the run will always be the most accurate, but
also the most timeconsuming proc.

*Small fragments tend to loose to much of the EtBr during the run
(rem. always equlibrium betweeen bound and unbound EtBr, EtBr and DNA
runs opposite ways in the gel -> small bands run faster and loose

On Mon, 04 Feb 2002 19:40:19 -0800, D Picton <pictond at>

>I was wondering if anyone has ever tried or knows why Ethidium Bromide
>is not added to Loading buffer? I've never run across an article where
>Ethidium Bromide is present in the Loading Buffer, it's allways
>present either in the gel or as a post electorphoresis step.
>D Picton

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