alexa fluor 647 dry vs wer

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Jill Herschleb Jill Herschleb
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alexa fluor 647 dry vs wer

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Hello,

I am using single alexa fluor 647 molecules to tag biomolecules of interest.  I
don't have a ton of experience in this field, and was wondering if someone would
be able to point me in the right direction.

Issue:  Imaging the single alexa 647 molecules in a dry environment
(immobilized on a cover glass) is easy, and the fluors are easy to detect and
enumerate.  However, using the same immobilized A647 probes on the same
surface, when I add an wet mounting media (I've tried Invitrogen Slowfade -
glycerol, sodium phosphate buffer with or without b-ME), I can still see the fluor
molecules, but they are much dimmer than when they are dry.

Has anyone experienced this before?  The wet mounting media does not seem to
affect the brightness of other fluors (Cy3, Alexa594).  So far I'm having the most
trouble with Alexa 647.

Thank you for your advice!  Sincerely,  Jill
George McNamara George McNamara
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Re: alexa fluor 647 dry vs wer

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In the microarray field there were stories a couple of years ago of
ozone killing the fluorophores (Cy5, a not-quite-identical twin of
AF647) in dry air. Apparently typical lab ozone levels is high enough to
be a CyDye-killer.

George
p.s. Protasenko et al 2005 -
http://chemeducator.org/sbibs/s0010004/spapers/1040269mk.htm - obtained
nice TIRF results with a 1.25 NA oil immersion lens under your dry
conditions:
"The purpose of this paper is to describe the assembly, from commercial
off-the-shelf components, of a low-cost (~$3300) optical microscope
capable of single-molecule detection."


On 6/10/2013 11:50 AM, Jill Herschleb wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello,
>
> I am using single alexa fluor 647 molecules to tag biomolecules of interest.  I
> don't have a ton of experience in this field, and was wondering if someone would
> be able to point me in the right direction.
>
> Issue:  Imaging the single alexa 647 molecules in a dry environment
> (immobilized on a cover glass) is easy, and the fluors are easy to detect and
> enumerate.  However, using the same immobilized A647 probes on the same
> surface, when I add an wet mounting media (I've tried Invitrogen Slowfade -
> glycerol, sodium phosphate buffer with or without b-ME), I can still see the fluor
> molecules, but they are much dimmer than when they are dry.
>
> Has anyone experienced this before?  The wet mounting media does not seem to
> affect the brightness of other fluors (Cy3, Alexa594).  So far I'm having the most
> trouble with Alexa 647.
>
> Thank you for your advice!  Sincerely,  Jill
>
>    


--



George McNamara, Ph.D.
Single Cells Analyst
L.J.N. Cooper Lab
University of Texas M.D. Anderson Cancer Center
Houston, TX 77054