Rapid micro fluorescence in situ hybridization in tissue sections.

Area of Science:

• Biomedical Engineering
• Molecular Pathology
• Genetics

Background:

• Formalin-fixed paraffin-embedded (FFPE) tissues are crucial for diagnostics.
• Traditional fluorescence in situ hybridization (FISH) is time-consuming and probe-intensive.
• Need for rapid, efficient biomarker detection in FFPE samples.

Purpose of the Study:

• To develop and validate a micro fluorescence in situ hybridization (μFISH) method for rapid cytogenetic biomarker detection.
• To assess the efficiency of μFISH for human epidermal growth factor 2 (HER2) detection in breast FFPE tissue sections.
• To reduce probe consumption and hybridization time in FISH assays.

Main Methods:

• Utilized a non-contact microfluidic scanning probe (MFP) for localized FISH probe delivery on FFPE tissue sections.
• Employed oligonucleotide FISH probes in an ethylene carbonate-based buffer for rapid hybridization.
• Demonstrated probe recycling using hierarchical hydrodynamic flow confinements for sequential testing.

Main Results:

• Achieved rapid hybridization: <1 min for chromosome enumeration and 10-15 min for HER2 status assessment in FFPE sections.
• Reduced FISH probe consumption by approximately 100-fold.
• Decreased hybridization time by 4-fold, leading to an overall assay turnaround time of <3 hours.
• Demonstrated compatibility with standard FISH protocols and the Instant Quality FISH assay.

Conclusions:

• Micro fluorescence in situ hybridization (μFISH) offers a rapid and efficient method for biomarker detection in FFPE tissues.
• The μFISH method significantly reduces assay time and resource consumption.
• μFISH holds potential for integration into pathology workflows for enhanced diagnostic and prognostic analyses.