This library (UI-R-BT0) consists of a mixture of individually tagged normalized libraries constructed from rat hippocampus, thalamus, mid-brain, medulla, corpus striatum, cerebral cortex and testis. The tag used to identify the source tissue is a string of 3-6 nucleotides present between the Not I site and the oligo-dT track which allows identification of the library of origin of a clone within the mixture. This library was then subtracted using a driver consisting of a mixture of all clones from UI-R-A0, UI-R-A1, UI-R-E0, UI-R-E1, UI-R-C0, UI-R-C1, UI-R-C2 and UI-R-C2p.