Table 1 - A strategy to identify genomic expression at single-cell level or a small number of cells

Table 1. Traditional functional genomics *.

Methods	Minimum Material	Throughput	Sequencing	Application
Sequencing base
EST	1-5 ug polyA RNA	High	High	gene expression
SAGE	1-5 ug polyA RNA	High	High	gene expression
Gel base
DD	10-100 ng polyA RNA	Medium	Low	Parallel gene expression
Colony base
Subtractive cloning	10-100 ng polyA RNA	Medium	Low	Parallel gene expression
Hybridization base
Microarray	>1 ug polyA RNA	High	N/A	Parallel gene expression
Protein base #
Two-D gel electrophoresis	10⁶-10⁷ cells	High	N/A	Parallel protein expression
Mass spectrometry	10⁵-10⁶ cells	High	N/A	Parallel protein expression
Functional array
Repressor system	N/A	N/A	Low	Protein-protein reaction
Yeast- library system	N/A	N/A	Medium	Protein