TROPLIST: Morpholino losing activity in solution over time

[Jon D.Moulton]

Hi Ira,

Morpholinos typically ship in glass, but the labels might smear on 
autoclaving so it is good to copy off any information needed.  The 
fluorescein is stable in the autoclave, but keep it in a dark place 
until used.

Regards,

  - Jon

ilblitz@uci.edu wrote:
> Hi Jon,
>
> Question(s):  Can the vials that MOs were shipped in, which I think are
> some sort of plastic, tolerate the autoclaving you suggest?  And second,
> what about the fluorescein modification carried on this particular MO?
>
> Ira
>
>   
>> Hi folks, it's Jon from Gene Tools.
>>
>> We've learned that Morpholinos can associate with the inside walls of
>> their containers, decreasing the solution concentration.  Many oligos
>> don't do this, but it has occurred often enough that we now suggest
>> keeping your Morpholino solutions at room temperature.  People whose
>> labs have switched from cold storage to room temperature storage haven't
>> been reporting any more problems with loss of activity.  If you have an
>> oligo that has lost activity and the heating protocol Ira wrote about
>> isn't bringing the activity back, try autoclaving the solution (with the
>> vacuum dry cycle disabled).  Morpholinos can take the heat, though I
>> wouldn't do it routinely, and the solvent collisions might be energetic
>> enough to knock the oligos off the walls.
>>
>> For storage, I would wrap the vial closure in Parafilm (to help keep
>> microbes out) and put the oligos in a dark box (to avoid photobleaching
>> fluorochromes) on a lab shelf.  They should be fine for years that way.
>>
>> Best wishes,
>>
>>   - Jon
>> jmoulton@gene-tools.com
>>
>> Dear Troplisters,
>>
>> I would like to ask you if you have found that some of your morpholino
>> oligos might have lost their "activity" over time?  I have just determined
>> that a morpholino I have been keeping at -20oC for the past 5 years and
>> now have a reason to dig out for an experiment, no longer has the youthful
>> vigor it once did.  I am aware that many people heat their morpholinos to
>> 65oC for a short time before injecting, to improve solubility, etc.  This
>> also failed to divert my embryos from their normal development.  So I
>> thought I'd send out this email to see what others in the community have
>> experienced.  Thanks for any comments you might have.
>>
>> Sincerely,
>>
>> Ira
>>
>>
>>
>>     
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