ZytoLight^® CEN 8 Probe

ZytoLight^® CEN 8 Probe (Prod. No. Z-2004) is a direct-labeled fluorescence in situ hybridization (FISH) probe targeting the centromeric region of chromosome 8 (alpha satellite DNA locus D8Z2, 8p11.1–q11.1). The probe designed for the identification and enumeration of human chromosomes, specifically targeting the centromeric regions of chromosomes. It produces sharp, bright signals specific for chromosome 8, aiding in the detection of genetic aberrations such as translocations, deletions, and chromosomal aneuploidies in formalin-fixed, paraffin-embedded (FFPE) tissue sections or cytology specimens.Principle:ZytoLight^® CEN probes are direct-labeled FISH probes that hybridize to highly repetitive human satellite DNA sequences located mainly at the centromeric regions of the respective chromosome. After denaturation of target DNA, the fluorophore-labeled probe binds specifically to its complementary centromeric sequences; the hybridized probe is then visualized by fluorescence microscopy using appropriate filter sets without the need for secondary fluorophore‑coupled antibodies. Full-spectrum light from the microscope lamp is narrowed by an exciter filter to a defined wavelength that excites the probe fluorochrome; emitted longer‑wavelength light passes a dichroic mirror and is restricted by a barrier filter so that only the specific emission signal is detected.Components:ZytoLight® CEN 8 Probe is composed of:

• ZyGreen (excitation 503 nm/emission 528 nm) labeledpolynucleotides (~4.5 ng/µl), which target sequences mapping in8p11.1-q11.1 specific for the alpha satellite centromeric regionD8Z2 of chromosome 8.
• Formamide based hybridization buffer

The probe is intended for identification and enumeration of chromosome 8 copy number in human interphase cells and as an adjunct to standard karyotyping in metaphase preparations. It is used to detect numerical aberrations (aneuploidies) of chromosome 8 in FFPE tissue sections or cytology specimens as part of FISH-based analysis of chromosomal aneuploidies.

In a normal interphase nucleus, use of chromosome enumeration probes specific for autosomes such as CEN 8 is expected to yield two distinct fluorescent signals per nucleus, corresponding to the two copies of chromosome 8. Deviations from this pattern (e.g., one, three, or more signals) indicate numerical aberrations of chromosome 8 and should be interpreted in the context of overall chromosome enumeration, sample type, and control results. Two major factors influencing FISH analysis quality are the choice of fluorochromes for the FISH probes and the use of appropriate microscope filter sets matched to these fluorochromes.

ZytoLight is a registered trademark of ZytoVision GmbH in Germany