Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Part of your problem may be that mitochondria contain a
carboxylase that uses biotin as a cofactor.  As a result, very
sensitive avidin conjugates detect the mitochondria without
additional biotin.  We showed that it was possible to take advantage
of this as a stain for mitochondria in developing retina.

Joel

Date sent:              Thu, 6 Nov 2003 07:08:57 +0100
Send reply to:          Confocal Microscopy List <[log in to unmask]>
From:                   Johan Dixelius <[log in to unmask]>
Subject:                streptavidin problem
To:                     [log in to unmask]

> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> Hi!
>
> I am trying to detect a biotinylated protein on cells.
> Streptavidin-Alexa488 gave background staining (e.g. mitochondria
> where nicely stained), and a weak signal that could be the specific
> one. Do you think that NeutrAvidin (molecular probes) or a
> antibiotin-antibody whould give lower background? How should I
> increase the specific signal? Whould R-PE be better, or is it to
> bulky? Is Fluosphere-conjugated NeutrAvidin an alternative?
>
> Johan
>
> Johan Dixelius
> Uppsala Universitet
> Inst. för Med. Genetik och Patologi
> Rudbeckslaboratoriet
> Dag Hammarskjölds väg 20
> 751 85 Uppsala
>
> Tel     018/471 46 07
> Fax     018/ 55 89 31
>
> E-post  [log in to unmask]

Joel B. Sheffield, Ph.D
Department of Biology
Temple University
Philadelphia, PA 19122
Voice: 215 204 8839
e-mail: [log in to unmask]