Researchers at the Albert Einstein College of Medicine reported in the 16 November online issue of Nature Structural & Molecular Biology that they developed a new approach with fluorescent in-situ hybridization (FISH) that detects single mRNA molecules in single cells-allowing them to be measured for gene expression levels.  For certain “housekeeping genes” (e.g. that for adenosine deaminase), the researchers saw transcription at a fairly constant rate rather then in bursts as previously supposed.  See article abstract