We describe a method to enhance the sensitivity of eukaryotic cDNA detection in differential display (DD). Typically, DD protocols require between 200 and 500 ng RNA for each reverse transcription reaction. The addition of Escherichia coli RNA before reverse transcription of eukaryotic RNA increases the detection of DD patterns more than tenfold. The method broadens the applicability of DD and allows the identification of genes that are differentially expressed when the amount of eukaryotic RNA is limited.