A novel method for preparation of tissue microarray

Table 1 Comparison of gene, protein and tissue chips

	Gene chip	Protein chip	Tissue chip
Substrate	Definitive DNA or RNA (Oligo or cDNA)	Definitive proteins (antigens\antibodies, etc.)	Many tissue samples
Probes	Labelled DNA or RNA (Cy3 and Cy5-tyramide)	Labelled antigens or antibodies	Specific antigens or antibodies, as well as labelled DNA or RNA sequences
Target material	Various sequences of DNA or RNA	Multiple kinds of proteins	Morphology and DNA, RNA and proteins
Superiorities	Analyzing numerous genes simultaneously in the same sample	Analyzing numerous proteins simultaneously in the same sample	Profile of genes or proteins in numerous tissues or populations
Applications	Large-scale, parallel analysis of genetic alterations, functionsand drug researches at DNA and RNA level	Large-scale, parallel analysis of concentrations, functional activities or interactions of proteins	Large-scale, parallel in situ analysis of DNA, RNA and proteins associated with clinical endpoints in hundreds of cell types or tissues at one time