What are locus specific probes?
Locus-specific probes target a specific gene sequence of interest. These probes can be used to determine whether a gene is amplified, deleted, or present in a normal copy number. The ratio of gene to centromere number is used frequently in reporting whether a tumor is amplified or deleted for a particular gene.
What is a PNA probe?
PNA FISH probes hybridize to target DNA with high sensitivity and specificity mainly due to the electrical neutrality of its chemical structure. This trait enables PNA probes to be more efficient and useful in applying to FISH (fluorescent in situ hybridization) even at low concentrations.
What is PNA FISH?
Fluorescence in situ hybridization using peptide nucleic acid probes (PNA FISH) is a novel diagnostic technique combining the simplicity of traditional staining procedures with the unique performance of PNA probes to provide rapid and accurate diagnosis of infectious diseases; a feature that makes PNA FISH well suited …
What is the most accurate description of telomeres?
Telomeres are the protective caps on the ends of the strands of DNA called chromosomes, which house our genomes. In young humans, telomeres are about 8,000-10,000 nucleotides long. They shorten with each cell division, however, and when they reach a critical length the cell stops dividing or dies.
What is centromeric probe?
Chromosome Enumeration Probes are designed for identification and enumeration of human chromosomes in interphase cells and as an adjunct to standard karyotyping in metaphases.
What does FISH test detect in pregnancy?
This testing allows preliminary detection of trisomy for chromosomes 13, 18, and 21, numerical abnormalities of the sex chromosomes, and triploidy (three sets of all chromosomes, resulting in 69 chromosomes). Prenatal interphase FISH can be performed on uncultured amniotic fluid, chorionic villi, or fetal blood cells.
Is PNA a fluorescent?
PNA-based strand displacement probes Strand displacement probes consist of a fluorescence oligonucleotide probe strand annealed to another oligonucleotide strand that is labeled with a second dye and which can interact with the first dye by quenching or FRET.
What is the backbone of PNA?
Peptide nucleic acid (PNA) is an artificially synthesized polymer similar to DNA or RNA. PNA is not known to occur naturally but N-(2-aminoethyl)-glycine (AEG), the backbone of PNA, has been hypothesized to be an early form of genetic molecule for life on earth and is produced by cyanobacteria.
How telomeres affect aging?
Telomeres get shorter each time a cell copies itself, but the important DNA stays intact. Eventually, telomeres get too short to do their job, causing our cells to age and stop functioning properly. Therefore, telomeres act as the aging clock in every cell.
How are telomeres maintained?
Telomere length is maintained by a balance between processes that lengthen and those that shorten telomeres. Telomerase is a ribonucleoprotein polymerase that specifically elongates telomeres. In human cells telomere length is not maintained and telomerase is not active in some tissues.
What is a dual fusion probe?
Dual fusion probes are used to detect specific translocations associated with cancer. The two genes involved in the translocation are labeled in different colors (ex: the ABL gene on chromosome 9 is red and the BCR gene on chromosome 22 is green), a nearby gene on each chromosome is also labeled in the same color.