stability of cDNA

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sitara
sitara's picture
stability of cDNA

 Hi
Can anyone tell me, for how long can I store the cDNA without any loss in the stability? can it be stored more than a year?

Thanks a lot in advance

Ivan Delgado
Ivan Delgado's picture
Hi sitara,

Hi sitara,

The short answer to your question is: you should store your cDNA for as short a time as possible. cDNA is unstable so it will degrade even when stored at -20oC, which is how you should store your cDNA always. Since you are storing your cDNA at -20oC, every time you use it you will thawit, only to freeze it again. These freezing and thawing cycle in itself will destroy your cDNA after as little as two or three cycles.

The long answer to your question, based on my experience, is as follows: 

1. You can store cDNA at -20oC for a good month or two, as long as you are not thawing it and freezing it more than once.

2. If you are going to freeze and thaw your samples 2, 3 or even 4 times, I highly recommend aliquoting your cDNA into multiple tubes, that way you never freeze and thaw your sample more than once.

3. If long storage of cDNA is necessary, I would suggest keeping yourcDNA is some buffer, such as TE. cDNA in water is much more unstable than in a buffer.

4. While preparing cDNA is not the easiest, or quickest, process, if at all possible simply prepare a new batch of cDNA next time you need it, instead of storing cDNA for months at a time.

Hope this helps.

sitara
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Thanks a lot for the answer

Thanks a lot for the answer

sitara
sitara's picture
Thanks for your answer, To

Thanks for your answer, To add to this, if the cDNA is alreday degraded, what are the ways to identify it?, is it ok to know from the variation in the expression of the housekeeping or the reference gene for that cDNA4

Thanks

Nazunderwent
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hi guys cDNA is very fragile

hi guys cDNA is very fragile and need to be used as soon as  possible i always arrange my expermints to use the cDNA the same day of synthesis and great result has been recoverd all the time.

Ivan Delgado
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Hi sitara,

Hi sitara,

If the cDNA is already degraded my recomendation is not to use it. 

Ivan

vanebio
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 Hi,

 Hi,

I have a question concerning cDNA stability during transport.
I´m working in germany and I have cDNA that I have to send to Spain. I was thinking on sending it by post in a box filled with dry ice. But could it be possible to carry the cDNA in my suitcase, in a small box that only keeps the cDNA in cold?? Or is not stable to travel one day in that conditions?

Thank you very much,

Vanesa

Ivan Delgado
Ivan Delgado's picture
Hi Vanesa,

Hi Vanesa,

The box you describe sounds like it does not keep the cDNA frozen. Unless you can keep the cDNA frozen while traveling my suggestion is to ship it frozen in dry ice. 

Good luck

vanebio
vanebio's picture
 Hi Ivan,

 Hi Ivan,

I´ve been reading that it´s possible to ship cDNA in blue ice, but I definetly decided to send it in dry ice.

Thank you very much!!

Vanesa

SYBRman
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Perhaps people are confusing

Perhaps people are confusing mRNA with cDNA here. In my experience, cDNA is well preserved in -20C and can be used in PCR applications even years after preparation.  It is the unstable mRNA that needs to be reverse transcribed into cDNA (which is much more stable than mRNA) soon after extraction, otherwise it is prone to degradation from RNAses. 

Hope this helps.