Gene expression analysis

A number of methods has been developed to study gene expression. For a review of these systems, see Alba (2004). The most widely used is the microarray (next slide). Some others are:

Name of system	Brief description	Advantages	Disadvantages
Differential display	Uses low-stringency PCR, primers and gel electrophoresis to amplify and visualize cDNAs	Little RNA is required; parallel profiling is possible	Output not quantitative; positives difficult to confirm
cDNA-AFLP	Uses the principles of AFLP with cDNA templates	Higher-stringency leads to clearer data which can be quantified; wide variety of tissue types, developmental stages or time points can be compared	Substantial resources required for cloning and sequencing; less sensitive to low-abundance transcripts
SAGE (serial analysis of gene expression)‏	Combines differential display and cDNA sequencing techniques	Is quantitative	Laborious; requires extensive sequence information