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how long will a 1M DTT solution will last in -20C - (Aug/31/2009 )

Hello,
I'm trying to figure out how long is the DTT good for. I know some people store the loading sample buffer containing DTT in the -20 and use it. Will this be good, or is it better to add DTT every time u use loading buffer (for western blot). And if I have to add it new every time what is the best way to do this. Weighing the grams of DTT and adding it to the loading buffer, or can I have a solution stock?

Right now I have 2x loading buffer with DTT that I stored in -20C I want to use it but I don't know if I have to add fresh DTT. I also boil the sample 5min @ 95C.

-medchemgirl-

medchemgirl on Aug 31 2009, 11:31 AM said:

Hello,
I'm trying to figure out how long is the DTT good for. I know some people store the loading sample buffer containing DTT in the -20 and use it. Will this be good, or is it better to add DTT every time u use loading buffer (for western blot). And if I have to add it new every time what is the best way to do this. Weighing the grams of DTT and adding it to the loading buffer, or can I have a solution stock?

Right now I have 2x loading buffer with DTT that I stored in -20C I want to use it but I don't know if I have to add fresh DTT. I also boil the sample 5min @ 95C.


I keep aliquots of DTT stored at -20°C, and add freshly thawed DTT to my loading buffer every time with good success.

-Dr Teeth-

Thanks!
I read that DTT gets oxidized very quickly even when stored at -20, so I was confused about if I could still use it. Do you have 1M stock or is it more concentrated?


Dr Teeth on Aug 31 2009, 10:50 AM said:

medchemgirl on Aug 31 2009, 11:31 AM said:

Hello,
I'm trying to figure out how long is the DTT good for. I know some people store the loading sample buffer containing DTT in the -20 and use it. Will this be good, or is it better to add DTT every time u use loading buffer (for western blot). And if I have to add it new every time what is the best way to do this. Weighing the grams of DTT and adding it to the loading buffer, or can I have a solution stock?

Right now I have 2x loading buffer with DTT that I stored in -20C I want to use it but I don't know if I have to add fresh DTT. I also boil the sample 5min @ 95C.


I keep aliquots of DTT stored at -20°C, and add freshly thawed DTT to my loading buffer every time with good success.

-medchemgirl-

We use DTT containing loading buffer straight from the -20, it works fine. Some of out loading buffer has been stored for a year or more.

-bob1-

bob1 on Aug 31 2009, 06:12 PM said:

We use DTT containing loading buffer straight from the -20, it works fine. Some of out loading buffer has been stored for a year or more.


Good to know. In response to an earlier question, we store our DTT as 1 M stock.

-Dr Teeth-

DTT has an absorbance peak of 220 nm, while the oxidized form has a peak at 300 nm.

-tfitzwater-