Table 1.

Strengths and weaknesses of omics approaches.

Approach	Strengths	Weaknesses
Genomics	Gives all sequence information on exons (whole exome sequencing) and additionally on introns, promoters, enhancers, intergenic regions, etc (whole genome sequencing) Identifies essential alterations	Prediction of final biological effect limited
Epigenomics	Gives information on potential regulation of genes	Dynamic nature and differences between cell types is often not reflected Correlation to gene expression may be limited
Cistromics	Describes genome architecture Gives information on gene regulation	Limited to specific binding factors or histone modifications analyzed Necessitates validated tools (e.g., high-grade selective antibodies) Correlation to gene expression may be limitedExpensive
Transcriptomics	Global expression analysis May detect all splice variants Sensitive, high dynamic range and quantitative Cell-specific transcriptomes can be resolved in single-cell experiments	Represents only an intermediate step Differences between organ- and cell-specific transcriptomes Correlation to protein levels not always linear
Proteomics	Addresses final regulation level Proteins are the main cellular effectors	Some proteins are difficult to separate High dynamic range of proteome makes detection difficult Absolute quantification necessitates labeling Individual experiments give only limited coverage Post-translation modifications may have strong impact on activity but can be difficult to analyze
Metabolomics	Close to phenotype Allows repetitive sampling of accessible biofluids	High diversity of metabolites of which only fraction is measured May be difficult to analyze and interpret