title: Microfluidics-assisted fluorescence in situ hybridization for advantageous human epidermal growth factor receptor 2 assessment in breast cancer.
abstract: Fluorescence in situ hybridization (FISH) is one of the recommended techniques for human epidermal growth factor receptor 2 (HER2) status assessment on cancer tissues. Here we develop microfluidics-assisted FISH (MA-FISH), in which hybridization of the FISH probes with their target DNA strands is obtained by applying square-wave oscillatory flows of diluted probe solutions in a thin microfluidic chamber of 5 μl volume. By optimizing the experimental parameters, MA-FISH decreases the consumption of the expensive probe solution by a factor 5 with respect to the standard technique, and reduces the hybridization time to 4 h, which is four times faster than in the standard protocol. To validate the method, we blindly conducted HER2 MA-FISH on 51 formalin-fixed paraffin-embedded tissue slides of 17 breast cancer samples, and compared the results with standard HER2 FISH testing. HER2 status classification was determined according to published guidelines, based on average number of HER2 copies per cell and average HER2/CEP17 ratio. Excellent agreement was observed between the two methods, supporting the validity of MA-FISH and further promoting its short hybridization time and reduced reagent consumption.
authors.affiliation: Laboratory of Microsystems 2, École Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland.
authors.forename: Huu Tuan
authors.identifier: 0000-0001-6130-2828
authors.initials: HT
authors.lastname: Nguyen
authors.affiliation: Laboratory of Microsystems 2, École Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Trouillon
authors.affiliation: Laboratory of Microsystems 2, École Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland.
authors.forename: Seiya
authors.initials: S
authors.lastname: Matsuoka
authors.affiliation: Institute of Pathology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: Maryse
authors.initials: M
authors.lastname: Fiche
authors.affiliation: Institute of Pathology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: Laurence
authors.initials: L
authors.lastname: de Leval
authors.affiliation: Institute of Pathology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: Bettina
authors.initials: B
authors.lastname: Bisig
authors.affiliation: Laboratory of Microsystems 2, École Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland.
authors.forename: Martin Am
authors.initials: MA
authors.lastname: Gijs
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics*; D015342:DNA Probes / Q000235:genetics; D005260:Female; D018628:Gene Dosage; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D044085:Microfluidics / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D015342:DNA Probes; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human