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How do genetic tests examine chromosomes, genes, enzymes, hormones, or amino acids?
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diagnosis
Magnetic resonance imaging (MRI) is a powerful diagnostic technique that is used to visualize organs and structures inside the body without the need for X-rays or other radiation.
Diagnostic genetic testing employs various specialized techniques to analyze biological components, depending on whether the target is chromosomal, genetic, or biochemical.1
Chromosomal and Genetic Analysis
- Cytogenetic Analysis: To examine chromosomes, cells are extracted from tissues like blood, skin, or bone marrow. Techniques such as G-banding, Q-banding, and C-banding use specific stains to identify structural malformations.2
- Molecular Assays: To investigate genes and DNA, methods like PCR and recombinant DNA technology allow for the isolation and cloning of DNA fragments to detect mutations. FISH uses fluorescent probes to detect specific DNA sequences or chromosomal deletions.32
Biochemical Analysis
- Enzymes, Hormones, and Amino Acids: Biochemical assays analyze these substances, often in blood or urine. Techniques like chromatography separate amino acids based on chemical affinities to identify defects. Enzyme analysis measures the activity of specific enzymes in blood serum; elevated levels often indicate that enzymes have leaked from injured cells into the circulation. Electrophoresis is also used to separate protein components to reveal structural differences.145