What is "q-fish"

Quantitative Fluorescent in situ hybridization (Q-FISH) is a cytogenetic technique based on the traditional FISH methodology. In Q-FISH, the technique uses labelled ( Cy3 or FITC) synthetic DNA mimics called peptide nucleic acid (PNA) oligonucleotides to quantify target sequences in chromosomal DNA using fluorescent microscopy and analysis software. Q-FISH is most commonly used to study telomere length, which in vertebrates are repetitive hexameric sequences (TTAGGG) located at the distal end of chromosomes. Telomeres are necessary at chromosome ends to prevent DNA-damage responses as well as genome instability. To this day, the Q-FISH method continues to be utilized in the field of telomere research.