The Gene Expression Barcode 2.0

http://rafalab.jhsph.edu/barcode/

The barcode algorithm is designed to estimate which
genes are expressed and which are unexpressed in a
given microarray hybridization. The output of our
algorithm is a vector of ones and zeros denoting
which genes are estimated to be expressed (ones)
and unexpressed (zeros). We call this a gene
expression barcode.

McCall et al., "The Gene Expression Barocde: leveraging
public data repositories to begin cataloging the human and
murine transcriptomes"
Nucleic Acids Research. 2011 Jan;39(suppl 1):D1011-D1015