*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Hi Simon,

I have been recently working with the HaloTag although I did no direct comparison to any FP. I mainly used the HaloTag-TAMRA ligand and to a lesser extend the HaloTag-AF488 ligand in combination with slightly overexpressed proteins. Based on older experiments with GFP, my subjective impression is that the Halo Tag might be slightly brighter. However, I think the main advantage is really the flexibility and the ability to selectively stain surface proteins, e.g. to study receptor internalization.

Best regard
Matthias

Dr. Matthias Faßler | Application Scientist
PerkinElmer | For the Better
[log in to unmask]
Phone:  +49 (0)40 307090-466 |   Fax:  +49 (0)40 307090-488
Schnackenburgallee 114, 22525 Hamburg, Germany
www.perkinelmer.com
Please consider the environment before printing this e-mail.
This e-mail message and any attachments are confidential and proprietary to PerkinElmer, Inc.  If you are not the intended recipient of this message, please inform the sender by replying to this email or sending a message to the sender and destroy the message and any attachments.  Thank you.


-----Original Message-----
From: Simon Walker [mailto:[log in to unmask]]
Sent: Wednesday, August 01, 2012 11:13 AM
Subject: Halo/SNAPtag vs GFP

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear List,
Advice please.  We're at the planning stage of some exps where we're going to try and image fluorescently-labelled proteins expressed at low level in live cells from a knock-in mouse.  We're going to need the signal to be as bright as possible and we're weighing up the pros and cons of Halo/SNAPtag vs fluorescent protein labelling.  Clearly there are advantages in the flexibility of labels that Halo/SNAPtag gives, but in terms of absolute signal is there a clear winner here?  I'm sure there are good theoretical arguments based on quantum yield, stoichiometry etc as to why one should be better, but has anyone directly compared the fluorescence signal from a Halo/SNAPtag labelled protein against a fluorescent protein label?
Thanks,
Simon

PerkinElmer Cellular Technologies Germany GmbH
Sitz Hamburg
Amtsgericht Hamburg, HRB 101440
Geschäftsführer: Achim von Leoprechting