Here the authors demonstrate that the absolute number of transcripts can be estimated. The novel methods presented in this publication - entitled "Genome-wide estimation of transcript concentrations from spotted cDNA microarray data" - will enable scientists to compare expression in different studies, between and within tissues.
Heidi Lyng and Debbie Hege Svendsrud are members of Group for Molecular Radiation Biology , which is led by Trond Stokke, at the Institute for Cancer Research.
The method has also in a recent BMC Genomics paper - entitled Limitations of mRNA amplification from small-size cell samples, from Eivind Hovig's group at the Norwegian Radium Hospital - been applied to demonstrate the importance of the quantitative aspect when analyzing small cell numbers.
Genome-wide estimation of transcript concentrations from spotted cDNA microarray data (Nucleic Acids Res. 2005 Oct 4;33(17):e143.)
Group for Molecular Radiation Biology (radium.no/stokke)
Norwegian Computing Center - information about Transcount
Eivind Hovig's group at the Norwegian Radium Hospital
News article from Hovig's web page: Enzymatic amplification is not the solution to profiling of very small cell samples