"Omics" technologies

The complete sequencing of the human genome has introduced us in a new era of research methodology referred as omics technologies. This term comprises high-throughput experimental technologies characterized by automation, miniaturized assays and large-scale data analysis. These technologies are increasingly generating massive and complex genomic data sets so that interpreting functional consequences of millions of discovered genetic variants is one of the biggest challenges. Over the past few years omics technologies have revolutionized research projects.

There are five major types of high-throughput measurements that are commonly performed:

• Genomic: analysis of the DNA sequence (i.e., SNP).
• Transcriptomic: analysis of transcribed RNA (i.e., the simultaneous measurement of gene expression values in a cell or tissue type).
• Proteomic: determination of proteins present in a sample.
• Metabolomic:  identification and quantification of all metabolites in a sample.
• miRNAomics: regulatory mechanisms underlying control of transcription.

Schematic representation of omics technologies, their corresponding analysis targets, and assessment methods. Taken from Wu RD et al. JDR 2011; 90:561-572.

Below is a list of the various types of information obtained from some of the omics technologies (adapted from Sawyers CL. Nature 2008; 452: 548-52):

• DNA copy-number assessment: comparative genome hybridization to DNA microarrays.
• Mutation screening: DNA sequencing,  mass-spectrometry-based genotyping, mutation-specific PCR.
• Gene-expression profiling: microarrays, multiplex PCR, microRNA-expression profiling. 
• Proteomic profiling: mass spectrometry, phosphoproteomic profiling, mass spectrometry after immunoprecipitation with specific antibodies. 
• Metabolomic profiling: mass spectrometry.

Tissue microarrays (TMAs) are an ideal platform for validating the results obtained from large-scale transcriptomic and proteomic studies. The most commonly performed assays on tissue microarrays are immunohistochemistry for protein expression, in situ hybridization for RNA expression, and fluorescence in situ hybridization for DNA copy number.

TMAs accrue value over time and allow investigators to build u

p IHC

profiles for individual tumours, as demonstrated by the expression of six different biomarkers in a single tumour core. Taken from Brennan DJ et al. Cancer Genomics Proteomics 2007; 4:121-134.

2-D eletrophoresis is an important step in proteomics analysis. In the following video you can learn more about how to prepare 2-D gels:

This video shows microarray technology and applications:

1. Study the main omics technologies and identify their differences.
2. Know the methodology used by each omic subdiscipline.
3. Advantages and limitations related to omics technologies.
4. Be able to relate the omics methodologies with the distint type of research.
5. Familiarize yourself with the diverse types of analysis in proteomics.
6. Know what epigenomics referes to.