Re: colocalization analysis

Posted by Dan Stevens on
URL: http://confocal-microscopy-list.275.s1.nabble.com/colocalization-analysis-tp786850p788835.html

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Judy,

I'm going to stick my neck out an make a suggestion...

Co-localization is a correlation.  I suspected that statisticians can do a three
variable correlation with minimal difficulty.  I was interested, so I googled
around this idea with the following (half decent) results;

http://faculty.vassar.edu/lowry/ch3a.html

http://books.google.ca/books?
id=bmwhcJqq01cC&pg=PA1012&lpg=PA1012&dq=correlation+three+variables&so
urce=web&ots=I9IYZSS-kj&sig=mItL7gIHEWt3RuQydR7XY4-
PHsE&hl=en&sa=X&oi=book_result&resnum=4&ct=result

I think the short answer is, talk to a statistician.  As you mention, I have
never seen this implemented.

One caveat that I suspect you are aware of... In my experience people tend
to relate visual colocalization with physical association.  Very rarely do I see
anyone consider a negative control, and then a comparisson of correlation
coefficients between experimental and negative control to determine
significance.  I suspect that if you went this far, and then mixed in a third
variable (protein), it would be hard to obtain significance simply due to
resolution limitations.  Of course, this would depend on abundance and
distribution of protein(s) of interest.

Would be interested to hear thoughts if anyone has further suggestions.

Dan



------------------------
Dan Stevens, PhD
Cellular Imaging Specialist
Carl Zeiss Canada