Ultrasensitive multiplexed miRNA detection based on self-priming hairpin-triggered isothermal cascade reaction

We herein describe an ultrasensitive isothermal strategy to detect miRNAs in a multiplexed manner by utilizing self-priming hairpin-triggered cascade reaction and adsorption property of graphene oxide (GO). In principle, the...

Smartphone-Based Device for Colorimetric Detection of MicroRNA Biomarkers Using Nanoparticle-Based Assay

The detection of microRNAs (miRNAs) is emerging as a clinically important tool for the non-invasive detection of a wide variety of diseases ranging from cancers and cardiovascular illnesses to infectious diseases. Over the years, miRNA detection schemes have become accessible to clinicians, but they still require sophisticated and bulky laboratory equipment and trained personnel to operate. The exceptional computing ability and ease of use of modern smartphones coupled with fieldable optical detection technologies can provide a useful and portable alternative to these laboratory systems. Herein, we present the development of a smartphone-based device called Krometriks, which is capable of simple and rapid colorimetric detection of microRNA (miRNAs) using a nanoparticle-based assay. The device consists of a smartphone, a 3D printed accessory, and a custom-built dedicated mobile app. We illustrate the utility of Krometriks for the detection of an important miRNA disease biomarker, miR-21, using a nanoplasmonics-based assay developed by our group. We show that Krometriks can detect miRNA down to nanomolar concentrations with detection results comparable to a laboratory-based benchtop spectrophotometer. With slight changes to the accessory design, Krometriks can be made compatible with different types of smartphone models and specifications. Thus, the Krometriks device offers a practical colorimetric platform that has the potential to provide accessible and affordable miRNA diagnostics for point-of-care and field applications in low-resource settings.

The Value of MicroRNA-375 Detection for Triaging Primary Human Papillomavirus Positive Women: A Cross-Sectional Study in a General Population

PurposeThis study aims to validate the value of microRNA (miRNA) detection for triaging human papillomavirus (HPV)-positive women in the general population.Patients and MethodsmiR-375 detection in cervical exfoliated cells has been demonstrated to have the superior value to cytology in triaging primary HPV-positive women in the hospital population. In this study, residual samples of cervical exfoliated cells from 10,951 women in a general population were used to detect miRNA. The performance efficiency of miRNA detection in identifying high-grade cervical intraepithelial neoplasia (CIN) was evaluated. Pearson chi-square test and McNemar pairing test were used to compare miRNA detection and cytology.ResultsIn valid 9,972 women aged 25–65, miR-375 expression showed a downward trend along with an increase in cervical lesion severity. The expression level of miR-375 ≤1.0 × 10-3 was identified as positive. In the HPV-positive and 12 HPV genotypes other than 16/18 (HR12)-positive women, miR-375 detection showed equivalent sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to that of cytology (≥ASC-US) and higher or similar sensitivity and NPV but lower specificity and PPV than that of cytology (≥ASC-H) in identifying CIN3+ and CIN2+. In HPV 16-positive women, miR-375 positivity had higher sensitivity and NPV but lower specificity and PPV than that of cytology (≥ASC-H and HSIL) in identifying CIN3+ and CIN2+. The immediate CIN3+ risk of miR-375 positivity was 19.8% (61/308) in HPV-positive, 10.8% (22/204) in HR12-positive, and 43.5% (37/85) in HPV16-positive women, respectively.ConclusionThe detection of miR-375 in cervical exfoliated cells may be an optional method for triaging primary HPV-positive women in population-based cervical cancer screening.

Rolling Circle and Loop Mediated Isothermal Amplification Strategy for Ultrasensitive miRNA Detection

Rolling circle amplification (RCA) and loop mediated isothermal amplification (LAMP) were combined to establish the rolling circle and loop mediated isothermal amplification (RC-LAMP) method for miRNA detection. With the participation of Bst 2.0 DNA Polymerase, the method enabled RCA and LAMP amplification to occur simultaneously without thermal cycling. The limit of detection of RC-LAMP was 500 amol/L, which is comparable to previously reported amplification strategies. Moreover, its upper limit of quantitation was higher and showed a stronger resistance to matrix interference. Therefore, it is possible to detect low concentrations of miRNA in samples by increasing the total RNA added. Owing to its facile detection mode and simple operation, this method has great potential in clinical sample detection.