ABSTRACT
Differential display (DD), as rst described by Liang et al.1,2 in 1992, is a reverse transcription (RT)–PCR-based method for rapid identi cation of differentially expressed genes. It offers several advantages over conventional methods,3 such as differential screening of cDNA libraries and subtractive cDNA library preparation and screening (see Chapter 12). First, employing PCR reduces the amounts of starting RNA needed, and at the same time enables ampli cation of transcripts, thus permitting detection of lower abundance mRNA species that are frequently undetectable using hybridization-based methods (e.g., conventional subtractive library screening). Second, the entire DD procedure from RNA extraction to banding pattern detection can be completed in a few days, whereas hybridization signals from library construction and screening-based approaches routinely take weeks to obtain. Third, DD is not limited to pairwise comparisons and can be readily expanded to compare transcript pro les among multiple, closely related samples, thus allowing time-course studies or developmental gradients to be followed. Although it does not offer high throughput like DNA microarrays do (see Chapter 29), it is versatile and relatively inexpensive to set up and perform in most molecular biology labs.
