title: Piezoelectric Plate Sensor (PEPS) for Analysis of Specific KRAS Point Mutations at Low Copy Number in Urine Without DNA Isolation or Amplification.
abstract: We have examined in situ detection of single-nucleotide KRAS mutations in urine using a (Pb(Mg1/3Nb2/3)O3)0.65(PbTiO3)0.35(PMN-PT) piezoelectric plate sensor (PEPS) coated with a 17-nucleotide (nt) locked nucleic acid (LNA) probe DNA complementary to the KRAS mutation without DNA isolation and amplification. In situ mutant (MT) DNA in urine in a wild type (WT) background was carried out at a flow rate of 4 mL/min and at 63 °C with the PEPS vertically situated at the center of the flow. Both the temperature and the impingement flow force discriminated the wild type. Under these conditions PEPS was shown to specifically detect KRAS MT in situ within 30 min with an analytical sensitivity of 60 copies/mL in a clinically relevant background of WT with concentrations 1000-fold greater than that of MT without DNA isolation, amplification, or labeling. For validation, detection was performed in a mixture of blue MT fluorescent reporter microspheres (FRMs) (MT FRMs) that bound to only the captured MT, and orange WT FRMs that bound to only the captured WT. The captured blue MT FRMs still outnumbered the orange WT FRMs by a factor of 4-1 even though WT was 1000-fold of MT in urine, illustrating the specificity of the point mutation detection.
authors.affiliation: School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, 10104, USA.
authors.forename: Ceyhun E
authors.initials: CE
authors.lastname: Kirimli
authors.affiliation: Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, 10104, USA.
authors.forename: Wei-Heng
authors.initials: WH
authors.lastname: Shih
authors.affiliation: School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, 10104, USA. shihwy@drexel.edu.
authors.forename: Wan Y
authors.initials: WY
authors.lastname: Shih
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D000074141:Circulating Tumor DNA / Q000652:urine; D004252:DNA Mutational Analysis / Q000379:methods*; D015342:DNA Probes; D018628:Gene Dosage; D006801:Humans; D008856:Microscopy, Fluorescence; D009154:Mutation; D017354:Point Mutation; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D012680:Sensitivity and Specificity
chemical_list: D000074141:Circulating Tumor DNA; D015342:DNA Probes; C117307:KRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)
keywords: Amplification-free hybridization detection; Biosensor; Cell-free point-mutation detection; Piezoelectric plate sensor; Piezoelectric sensor