labelled cDNA stability?

Dear all,

I was wondering if you had an idea of the labeled cDNA stability at -
20C. I had prepared some labeled cDNA a couple of months ago and had
prepared some microarrays with it. 6 weeks after, I decided to do
another series of microarrays from the same labeled cDNA because I
still had plenty, but the results are completely different. The only
reason I can see for this would be that my labeled cDNA was too old,
although I thought it was fairly stable...

Thanks for your help,

Claire.

[Only registered users see links. ] wrote:

Labelled how? Radioactive or fluorescent? Which fluorochromes? In
solution or precipitated/lyophilised? Which salts are present in the
solution, at what concentrations?

We generally use an indirect protocol (incorporate aminoallyl-dUTP,
then couple Cy dyes). The aminoallyl-labelled cDNA is stable for some
time, though we haven't had cause to go over a week. I wouldn't trust
Cy-labelled cDNA to remain stable in solution (gut feeling, no
empirical data).

Peter

Sorry about the lack of details!
It is indeed Cy3-labelled cDNA (and Cy-5 labelled gDNA) in Tris-HCl 1mM pH 7.5.

Claire.


[Only registered users see links. ] (Claire) wrote in message news:<fe8de6fc.0405182358.6a03b42c@posting.google. com>...

"Peter Ellis" <[Only registered users see links. ].uk> wrote in message
news:[Only registered users see links. ] t...

Hi,
we stored both amino-allyl and Cy labelled cDNA and aRNA at minus 80 degrees .
Still worked OK after 2 month ; no longer storage tried (yet)

We did notice deterioration of the microarray's stored at rt over sillica in a
few month. Oligo's in betaine/SSC printed on ultragaps fixed with UV. Array's
stored at rt in vaccuum over sillica were still OK after 1.5 years.
Been at this place ? :

[Only registered users see links. ]

hth
Gys