“…However, SAGE analysis of nephron segments, glomeruli, or kidney cells, which can be obtained by laser capture microdissection of biopsy specimens [14, 15], is only practical, if significantly smaller amounts of mRNA can be used for cDNA synthesis. To address this problem, several groups have developed ‘miniaturized’ protocols that require 500- to 5,000-fold less input RNA, i.e., from as few as 15,000–50,000 cells [16, 17, 18]. In addition, quantitative techniques for RNA amplification from small samples have been published [15]which allow expression libraries to be generated from considerably fewer cells.…”