A recurrent problem in surgical pathology specimens is specimen mix-up and contamination of a patient's specimen by "floaters." While many of these cases can be resolved histologically or immunophenotypically using blood group antigen immunohistochemistry, a significant number of cases may not be resolved by these modalities and can have serious clinical and medicolegal implications. Use of fluorescence in situ hybridization (FISH) to perform sex genotyping on tissue specimens with potential tissue contaminants is an effective and reliable means of potentially resolving problems of floater contamination. Minute tissue samples provide sufficient target DNA and nuclei for FISH studies.
This assay confirms the presence of these sex chromosomes within the cells of interest. Presence of two green X chromosome signals is indicative of an XX female genotype, whereas the presence of a single green X chromosome and single orange Y chromosome signal are indicative of an XY male genotype.
Probe type: Dual color enumeration
Disease State: Identification of Floaters
CPT Code(s): 88366 (reference only; CPTs may vary)
Turnaround Time: Within 3-4 business days of receipt
Schedule: Monday - Friday
• Formalin-fixed, paraffin-embedded tissue block or cell block - OR -
• Minimum of 5 unstained slide cut at 4µm for each test requested