ZytoLight^® SPEC TFE3 Dual Color Break Apart Probe

The ZytoLight^® SPEC TFE3 Dual Color Break Apart Probe is a directly labeled fluorescence in situ hybridization (FISH) probe designed for the qualitative detection of translocations involving the TFE3 gene at Xp11.23. The ZytoLight^® system utilizes direct labeling, eliminating the need for fluorophore-coupled antibodies and streamlining the FISH workflow. For optimal results, the probe should be used in combination 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 TFE3 Dual Color Break Apart Probe comprises:

• ZyGreen (excitation 503 nm/emission 528 nm) labeled polynucleotides (~10.0 ng/µl), targeting sequences mapping in Xp11.23* (chrX:48,906,685-49,509,699) proximal to the TFE3 breakpoint region;
• ZyOrange (excitation 547 nm/emission 572 nm) labeled polynucleotides (~4.5 ng/µl), targeting sequences mapping in Xp11.23* (chrX:48,287,169-48,792,674) distal to the TFE3 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 TFE3 gene at Xp11.23 by fluorescence in situ hybridization (FISH)

Using suitable filter sets, probe hybridization produces a green signal proximal to the TFE3 breakpoint and an orange signal distal to it.
Normal scenario: female cells or any cells without a TFE3 gene region translocation display two green/orange fusion signals during interphase. Male cells or cells without such a translocation show one orange/green fusion signal in interphase.
Aberrant scenario: if a translocation affects the TFE3 gene region, this is shown by one distinct green signal and one distinct orange signal.
Overlapping orange and green signals may appear yellow.

ZytoLight is a registered trademark of ZytoVision GmbH in Germany