Introduction

Molecular cytogenetics is now considered an integral part of the modern-day cytogenetics laboratory. The ability to identify specific sequences along a chromosome by molecular cytogenetic techniques has been especially useful in 1) defining cytogenetically detected chromosomal material of ambiguous or unknown origin; 2) detecting small submicroscopic rearrangements; 3) rapidly determining the ploidy for specific chromosomes at interphase, e.g., trisomy 21; and 4) mapping particular DNA sequences to specific chromosomes (gene mapping). These specific sequences have been identified by using fluorescently labeled DNA probes that hybridize to the DNA segment of interest. This technique is referred to as fluorescence in situ hybridization (FISH) and forms the fundamental basis of molecular cytogenetics. Since its development in the 1980s, molecular cytogenetics has expanded dramatically beyond two-color FISH. Comparative genomic hybridization (CGH) is one of the more recent innovative molecular cytogenetic techniques that have provided a very unique way to detect chromosomal imbalances in a single-step global-wide scan of the genome. Many factors have made CGH an attractive technique for cancer research, the primary one being that CGH is a DNA-based technique and thus specimen culturing and the availability and quality of metaphase spreads from the specimen are not considerations. This property makes formalin-fixed paraffin-embedded neo-plastic tissue and even nonviable tissues, such as that derived from the products of conception, amenable to analysis by CGH. Comparative genomic hybridization has also proved to be an invaluable tool in clinical cytogenetic analysis, especially for samples for which a complete and detailed karyotype could not be obtained by conventional methods. The ability to obtain a genome-wide search for imbalances without any prior information of the chromosomal aberration in question has been particularly useful in clinical cytogenetics. This chapter discusses the technique of CGH and describes its use as both a cancer research tool and a diagnostic technique in clinical cytogenetics.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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