ZytoLight^® SPEC ALK Dual Color Break Apart Probe

The ZytoLight^® SPEC ALK Dual Color Break Apart Probe (PL81) is a direct-labeled FISH probe for the qualitative detection of translocations of the human ALK gene at 2p23.1-p23.2 in formalin-fixed, paraffin-embedded specimens, using fluorescence in situ hybridization (FISH). The probe is intended for use with the ZytoLight FISH-Tissue Implementation Kit.

ZytoLight^® probes enable the precise identification of genetic abnormalities, including translocations, deletions, amplifications, and chromosomal aneuploidies, in formalin-fixed, paraffin-embedded (FFPE) tissue sections or cytology specimens, without the need for additional antibody-based detection.

Components

The ZytoLight SPEC ALK Dual Color Break Apart Probe comprises:

• ZyGreen (excitation 503 nm/emission 528 nm) labeled polynucleotides (~10.0 ng/µl), targeting sequences mapping in 2p23.1-p23.2* (chr2:29,460,144-30,095,822) proximal to the ALK breakpoint region;
• ZyOrange (excitation 547 nm/emission 572 nm) labeled polynucleotides (~4.5 ng/µl), targeting sequences mapping in 2p23.2* (chr2:29,174,204-29,383,335) distal to the ALK breakpoint region;
• Formamide based hybridization buffer

*according to Human Genome Assembly GRCh37/hg19

Principle

The fluorescence in situ hybridization (FISH) method enables the identification and visualization of particular nucleic acid sequences within cell samples. DNA fragments labeled with fluorescent dyes, known as FISH probes, are co-denatured with their complementary target DNA strands in the sample and then allowed to hybridize. Following hybridization, non-specific and unbound probe fragments are removed through stringency washes. The DNA is then counterstained with DAPI, and the hybridized probes are detected using a fluorescence microscope equipped with filters matched to the specific fluorochromes used to label the FISH probes.

This probe is intended for use in formalin-fixed, paraffin-embedded specimens, to qualitatively detect translocations of the human ALK gene at 2p23.1-p23.2, via FISH.

Using suitable filter sets, the hybridization signals of the probe appear green near the ALK breakpoint region and orange away from the ALK breakpoint region.

• Normal scenario: in normal cells during interphase or cells without a translocation of the ALK gene region, two green/orange fusion signals are observed.
• Aberrant scenario: one translocated ALK gene region is shown by one separate green and orange signal each. An EML4-ALK inversion with 5’-ALK sequence deletion is shown by one or multiple isolated orange signals.

Overlapping signals may appear yellow.

ZytoLight is a registered trademark of ZytoVision GmbH in Germany