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

Calcein-AM is better FDA for labeling the cell interior. Calcein has 4 
negative charges (maybe five) and is well retained. Also, calcein unlike 
FDA is insensitive to physiological pH changes.

John

Randy Learish wrote:
> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> On this topic, I was wondering how well the chloro-methylated dyes are 
> retained.  The Probes handbook says these dyes have "mild" thiol-reactivity 
> which would explain why the Tracker dyes are better retained in living cells.  
> But does that mean they actually cross-link to proteins?  If I lysed the cells 
> after labeling, would I see fluorescently labeled proteins on SDS-PAGE?
>
> Randy
>
>
>   

-- 
John J. Lemasters, MD, PhD
Professor and South Carolina COEE Endowed Chair
Director, Center for Cell Death, Injury and Regeneration
Departments of Pharmaceutical Sciences and Biochemistry & Molecular Biology
Medical University of South Carolina
QF308 Quadrangle Building
280 Calhoun Street, MSC 140
Charleston, SC 29425

Office: 843-792-2153
Lab: 843-792-3530
Fax: 843-792-1617
Email: [log in to unmask]