Biovideo: Introduction to Empire Genomics

Overview of aCGH

Genetic alterations such as amplifications and deletions often contribute to the development of tumorsAn abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells and serving no physiological function and other abnormal pathologies. These gene alterations modify normal cell growth, functionality, and communication pathways which may result in the emergence of diseases such as cancerA malignant and invasive growth or tumor, tending to recur after excision and to metastasize to other sites. The need to characterize these chromosomal aberrations is crucial if we are to gain a better understanding of the underlying mechanisms for disease which will, in turn, allow researchers to develop clinical approaches with unprecedented levels of specificity.

Empire Genomics utilizes a proprietary technique that allows for the detection of chromosomal aberrationsAny irregularity or abnormality of chromosome distribution, number, structure, or arrangement. Our superior genomic platform supports research and diagnostic applications in cancer biology, biomarkers, drug discovery, prenatal screening, developmental disorders, autism and many more genomic related areas.

Background

Comparative Genomic Hybridization (CGH) is a technique that was developed to survey DNA copy-number variations across the entire genome. Differentially labeled test and reference samples are hybridized to normal chromosomes, and fluorescence ratios along the length of the chromosomes provide a cytogenic representation of the relative copy-number variations.

Array-based Comparative Genomic Hybridization

In array-based Comparative Genomic Hybridization (aCGH), arrays of genomic BAC, P1, or cosmid cDNA clones are used for hybridization instead of the metaphase chromosomes which are utilized in the conventional CGH approach. Fluorescence ratios at arrayed DNA elements offer a locus-by-locus measure of DNA copy-number variations, which contributes to a significant increase in mapping resolution.

Advantages of aCGH

Empire Genomics capitalizes on advances made in genomic array technology for the detection of chromosomal and sub-chromosomal imbalances observed as copy number gains and/or losses. Classically, the structure and enumeration of chromosomes were studied using cytogenetics and G-banding techniques. More recent molecular cytogenetic methodologies were developed to examine copy number aberrations in the DNA content of cells without the need for culturing. This technique, known as array-based Comparative Genomic Hybridization (aCGH) is capable of detecting gains and losses in genomic regions 5-10 Mb in length. Empire Genomics has further evolved this technology by developing microarrays that utilize discrete segments of DNA generated from the RPCI BAC clones. The clones served as the intermediate templates for sequencing the human and mouse genomes and are now printed on glass slides by Empire Genomics as targets for aCGH. The copy number changes detected with the CGH arrays range from 175 Kb for the BAC arrays to 5-10 Kb for oligonucleotide arrays and are of considerable diagnostic value to disease conditions. This is a tremendous improvement from looking at entire chromosomes. In addition to blood, fresh and frozen tissue, even formalin-fixed paraffin-embedded (FFPE) archival material can be analyzed in as little as 24 hours.

Array-based CGH continues to transform the field of Cytogenetics by providing a high resolution, high-throughput technology for the accurate mapping and detection of chromosome aberrations