probesets with identical values in Affymetrix Hugene 2.1 platform

Question

[BrunoGiotti]

Hi all,

Do you have any idea if it's normal or not that different probesets mapping to a common gene have exactly same values of intensity? there are several probesets in a microarray data I'm working on that show this perfect identity over 28 samples.

Thank you

Answer 1

[bioinfoSeeker]

There can be multiple "unique: _at" probesets mapped to the same gene. This may be due to variants or due to availability better probeset design.

An FAQ on this topic at the affymetrix site: http://www.affymetrix.com/support/help/faqs/ge_assays/faq_16.jsp