ZytoLight^® SPEC ERG Dual Color Break Apart Probe

The ZytoLight^® SPEC ERG Dual Color Break Apart Probe (PL95) is a direct-labeled FISH probe for the qualitative detection of translocations of the human ERG gene 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 ERG Dual Color Break Apart Probe comprises:

• ZyGreen (excitation 503 nm/emission 528 nm) labeled polynucleotides (~10 ng/µl), targeting sequences mapping in 21q22.2* (chr21:40,078,039-40,850,582) distal to the ERG breakpoint region;
• ZyOrange (excitation 547 nm/emission 572 nm) labeled polynucleotides (~4.5 ng/µl), targeting sequences mapping in 21q22.13-q22.2* (chr21:39,171,790-39,733,849) proximal to the ERG 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.

For the qualitative detection of translocations involving the human ERG gene at 21q22.2 by fluorescence in situ hybridization (FISH)

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

• Normal scenario: in normal cells during interphase or cells without a translocation of the ERG gene region, two orange/green fusion signals are observed.
• Aberrant scenario: one deleted ERG gene region causing TMPRSS2-ERG fusion is shown by the loss of one green signal. Partial deletions of the ERG gene region might result in a normal signal pattern with smaller green signals. A signal pattern comprising one orange/green fusion signal, a separate green, and a separate orange signal indicates an ERG translocation without involvement of TMPRSS2 (e.g., SLC45A3-ERG).

Overlapping signals may appear yellow.

ZytoLight is a registered trademark of ZytoVision GmbH in Germany