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Sorry for bothering the list, but the first email sent just to you bounced back.
I would also appreciate receiving a copy. Thank you.
Judy

Judy Trogadis
Bio-Imaging Coordinator
St. Michael's Hospital, 7Queen
30 Bond St.
Toronto, ON M5B 1W8, Canada
ph:  416-864-6060  x6337
pager: 416-685-9219
fax: 416-864-6043
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>>> [log in to unmask] 05/18/07 3:55 AM >>>
Search the CONFOCAL archive at
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Colocalization covers two significantly different conditions ~ 
(a) that pixels have both fluorophores present
(b) that there is some relationship between the intensities of the fluorophores 

It is possible to completely meet that first criteria (presence of both fluorophores) in the absence any relationship between the inensities.
To reduce the confusion we suggest that mere presence should be called Cooccurence and Colocalization be used to refer to any relationship between intensities.

A serious problem is all colocalization measurements is the quality of the images, imperfect images reduce the measured Pearson colocalization coefficient ~  a very common measurement.
A requirement for high quality images appeared in the first quantitative colicalilzation paper Manders 1993.   BOLTE and CORDELIÈRES in their review In J Microscopy rediscover this problem and then conclude that the Pearson corelation coefficient is unusable. A completely over the top conclusion, see correspondence in forthcoming issue of J. Microscopy.
The requirement  is for either high quality images or for a method of compensating for image noise. 
 We have recently introduced a method for making accurate measurements from the less than perfect images we actually have. It was presented at the Biophysical Soc meeting at Baltimore and at the ELMI meeting in York. Contact us offline for copies.


Ingela Parmryd & Jeremy Adler
Cell Biology
The Wenner-Gren Inst.
Arrhenius Laboratories E5
Stockholm University
Stockholm 106 91
Sweden



-----Original Message-----
From: Confocal Microscopy List on behalf of Claire Brown
Sent: Tue 15/05/2007 15:05
To: [log in to unmask]
Subject: Re: Colocalisation extended
 
Search the CONFOCAL archive at
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There was also a recent review of co-localization methods that may be helpful.

A guided tour into subcellular colocalization analysis in light microscopy

    * S. BOLTE* *Plateforme d'Imagerie et de Biologie Cellulaire, IFR 87 'la
Plante et son Environnement', Institut des Sciences du Végétal, Avenue de la
Terrasse, 91198 Gif-sur-Yvette Cedex, France &
    * F. P. CORDELIÈRES?

http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2818.2006.01706.x