The invention provides novel compositions and methods for the analysis of gene expression (e.g., expression profiling) using microarray-based technology. In some embodiments of the invention, the novel methods use gene-specific as well as universal amplification primers during sample preparation, and the methods permit the simultaneous analysis of multiple samples on the same microarray. Furthermore, some embodiments of the invention incorporate barcode sequences into the amplified products, thereby permitting the use of generic arrays and generic labeled probes.