Table 2.

Advantages and disadvantages of different platforms for gene expression profiling

Feature	RNA-seq	Microarray	OpenArray®
Dynamic range (order of magnitude)	5	3	7–8
Price	High	Medium	Medium–low
Number of genes	Complete set of RNA families and splicings	Transcriptome. Usually, coding mRNAs and small RNAs	Maximum 56–128 genes per analysis
Probes	Neither design nor previous knowledge of sequences is required	Limitation for number of sequences, design and orientation of probes	Limitation for number of sequences, primers design
Sensitivity	High and low background	Low and high background	Very high and low background
Specificity	Very high	Depends on platform	Very high
Bioinformatics	Under development	Well developed	Very easy
Sample preparation	Complex. Requires specialized skills for cDNA library preparation	Easy	Easy
Time	Weeks	Days	Hours