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** vendor reply **

Hi, Simon,

There are two options for commercial solutions:

The first one, which you mention, is the BackDrop background suppressor.  You would want the green one (to match the wavelength of your background signal -- the kit comes with blue, green, and red).  We have used it here at Molecular Probes to quench background fluorescence of this sort.  It's non-cell-permeant and non-toxic for standard imaging times.

The second option is to forego your media and instead image in our Live Cell Imaging Solution (catalog A14291DJ), which we routinely use now for most of our general imaging assays here.  It has been validated for signal-to-background for fluorescence for live cell imaging at ambient atmosphere and temperature for up to four hours with a wide range of cell lines.  It's a buffered salt solution with HEPES, as described in the product manual.
https://products.invitrogen.com/ivgn/product/A14291DJ
http://tools.invitrogen.com/content/sfs/manuals/Live_Cell_Imaging_Solution_QRC.pdf


Cheers,

Jason

Jason A. Kilgore
Technical Application Scientist
Molecular Probes Labeling and Detection Technologies
Cells Systems Division
 
T 1 800 955 6288 then option 4, then option 6,  or  541 335 0353 . F 541 335 0238
29851 Willow Creek Rd . Eugene . OR . 97402-9132 . United States
www.invitrogen.com/technicalsupport

 



-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]] On Behalf Of Simon Walker
Sent: Thursday, September 13, 2012 8:04 AM
To: [log in to unmask]
Subject: Background fluorescence problem

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Dear List,
We are imaging very weakly fluorescent live cells (expressing GFP) on a wide-
field system and having issues with a source of background fluorescence.  
When we look at our cells under epi-illumination we see a rapid drop in a weak 
background signal (not where the cells are) that fully recovers over a ~10 s 
period after the illumination light is switched off.  Our experiments require the 
use of DMEM as the imaging medium and this is the likely cause of problem.  It 
appears that something in the medium is sticking to the coverglass.  It's not 
phenol red as the effect is seen with both phenol red-containing and phenol-
red-free DMEM.  Does anyone know what else it could be?  Has anyone else 
seen anything similar?  We're wondering if it could be riboflavin which is in the 
DMEM we're using.  Would this stick to glass?

I've seen that Life Technologies now market a substance that allegedly 
surpresses background fluorescence in DMEM:
http://products.invitrogen.com/ivgn/product/R37603
Has anyone tried this?  Does anyone know how it works?

Thanks,
Simon