--- Query Results ---

Program:Genetics and Genomics
Test Name:Ewing Sarcoma by FISH
Alternate Test Name:EWSR1 gene rearrangement
Performing Site: University of Alberta Hospital
Performing Dept:Molecular Pathology
Availability:Test set-up on Monday and Wednesday (excluding statutory holidays).
TAT:2 weeks
Preferred Tube/Container:See Specimen Requirements
Specimen Requirements:For Paraffin-Embedded Tissue:
1. A formalin-fixed, paraffin-embedded tissue block is preferred.
2. Alternatively, one slide stained with Hematoxylin & Eosin as well as six 4-micron baked (2 hours at 60C) unstained charged slides can be submitted.
3. Please provide a copy of the corresponding pathology report.
Requisition/Form:All requests MUST be submitted on a Molecular Pathology Requisition.
Please provide any pertinent clinical history on the requisition.
Indications:For investigation of Ewing Sarcoma.
Method:Fluorescence In Situ Hybridization
Method Details:Slides are cut from paraffin block and are deparaffinized in xylene and dehydrated in ethanol. Specimen pretreatment and fluorescence in situ hybridization (FISH) is performed using Vysis® (Abbott Molecular Inc.) pretreatment kit and appropriate probes as described below.

The LSI EWSR1 dual colour probe consists of a 500 kb SpectrumOrange (red) labeled probe that flanks the 5’ side of the EWSR1 gene, and extends inward into intron 4. The second probe is a 1100 kb SpectrumGreen (green) probe, which flanks the 3’ side of the EWSR1 gene. The known breakpoints within the EWSR1 gene are restricted to introns 7 through 10.

Normal nuclei contain two red/green (yellow) fusion signals (2F). In a normal cell that lacks a t(22q12) in the EWSR1 gene region, a two fusion signal pattern will be observed. In an abnormal cell with a simple t(22q12), the expected signal pattern will be one fusion, one red and one green signal.

This lab’s normal cut off is established at less than or equal to 10% of the cells showing an abnormal signal pattern. All appropriate negative and positive controls are used.

An average of 100 interphase nuclei are examined independently by two observers using an Olympus Provis Fluorescence microscope system on 1000X magnification.
Last Updated On:Tuesday, June 27, 2017
Date of Last Review:Jan 2 2018 12:00AM