A comparison of DP-TOF Mass Spectroscopy (MS) and Next Generation Sequencing (NGS) methods for detecting molecular mutations in thyroid nodules fine needle aspiration biopsies.

Mutations in the B-Raf proto-oncogene, serine/threonine kinase (BRAF), have been linked to a variety of solid tumors such as papillary thyroid carcinoma. The purpose of this study was to compare the DP-TOF, a DNA mass spectroscopy (MS) platform, and next-generation sequencing (NGS) methods for detecting multiple-gene mutations (including BRAFV600E) in thyroid nodule fine-needle aspiration fluid. In this study, we collected samples from 93 patients who had previously undergone NGS detection and had sufficient DNA samples remaining. The MS method was used to detect multiple-gene mutations (including BRAFV600E) in DNA remaining samples. NGS detection method was used as the standard. The MS method's overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 95.8%, 100%, 100%, and 88%, respectively in BRAFV600E gene mutation detection. With a kappa-value of 0.92 (95%CI 0.82-0.99), the level of agreement between these methods was incredibly high. Furthermore, when compared to NGS in multiple-gene detection, the MS method demonstrated higher sensitivity and specificity, 82.9% and 100%, respectively. In addition, we collected the postoperative pathological findings of 50 patients. When the postoperative pathological findings were used as the standard, the MS method demonstrated higher sensitivity and specificity, at 80% and 80%, respectively. Our findings show that the MS method can be used as an inexpensive, accurate, and dependable initial screening method to detect genes mutations and as an adjunct to clinical diagnosis.

Detection of HER2 amplification in formalin-fixed paraffin-embedded breast carcinoma tissue with digital PCR using two TFF3 sequences as internal reference.

PURPOSE: Droplet digital PCR (ddPCR) is a highly accurate method to determine DNA concentration and detect copy number variations. We developed an approach to assess HER2 gene amplification status using ddPCR with two sequences of TFF3 as reference probes. EXPERIMENTAL DESIGN: 76 templates of carcinoma DNA were prepared from formalin-fixed paraffin-embedded (FFPE) tissues. Digital PCR assay of the copy number of HER2 and TFF3 DNA was performed on the samples. The results were compared to prior fluorescent in-situ hybridation (FISH) assays performed on the same samples. RESULTS: The ddPCR assay had high concordance with the conventionally used immunohistochemistry (IHC) and FISH methods. The ddPCR method returned fewer indeterminate results than IHC. Concordance between a ddPCR plus FISH method and IHC plus FISH can rise to 98.7% (75/76) after validation is carried out. CONCLUSION: It's potentially possible to improve the sensitivity and specifity of HER2 ddPCR assays using reference sequences not co-localized with HER2 on chromosome 17, and combining results from multiple sequences. Adopting an approach based on ddPCR HER2 assays plus FISH could lead to reduced costs, labour, and time consumption compared to current IHC plus FISH standard, while not losing precision.

[Development of a single-tube PCR-pyrosequencing method for simultaneous and rapid detection of the genetic polymorphism of warfarin metabolizing enzymes].

The purpose of this article is to develop a new high throughput method for detecting genetic polymorphism of warfarin metabolism-related genes rapidly in a single tube. Genomic DNA from human peripheral blood was extracted, and amplified with biotinylated primer to obtain single-stranded templates for pyrosequencing. Then, the single-stranded tem-plates were subjected to Pyrosequencing analysis using PyroMark ID instrument. Simultaneously, Sanger sequencing was also applied to sequence the products as a control to check the reliability of the pyrosequencing result.. The results dis-played that three variants of the warfarin metabolism-related genetic polymorphism (CYP2C9*2, CYP2C9*3, and VKORC1(-1693)) could be simultaneously detected using three different sequencing primers in a single-tube (one test), and 96 tests could be carried out each time. Repeat test and reliability test indicated that the agreement between the pyrosequencing and the Sanger sequencing methods was 100%. . All of these demonstrated that pyrosequencing could accurately and rapidly detect the genetic polymorphism of the warfarin drug metabolism-related genes with high throughput. Compar-ing with simplex pyrosequencing, the method established in the present study was much more economical and timesaving. It has a great value in personalized medical treatment and could be extended to the other genetic diseases.

Use of Pyromark Q96 ID pyrosequencing system in identifying bacterial pathogen directly with urine specimens for diagnosis of urinary tract infections.

Detection and identification of bacterial etiology in urine is critical for accurate diagnosis and subsequent rational treatment of urinary tract infections (UTIs). Urine culture followed by a series of biochemical reactions is currently the standard method for detecting and distinguishing microorganisms associated with UTIs. The whole procedure commonly takes more than 24h. Here we developed a new system combining 16S rRNA gene broad-range PCR with pyrosequencing technology that allows for bacteria detection and identification in urine in 5h. To evaluate this system for rapid diagnosis of bacteriuria, 768 urine specimens were collected from patients with suspected UTIs and were tested side-by-side using standard urine culture-based identification method and the pyrosequencing method. The results from pyrosequencing correlated well with those from traditional culture-based identification method. The overall agreement between these two methods reached 98.0% (753/768). In addition, we tested the sensitivity of pyrosequencing method and determined that urine bacterial numbers as low as 10(4)cfu/ml could be accurately detected and identified. In conclusion, compared with traditional biochemical method, the PCR-pyrosequencing system significantly improved the detection and identification of bacteriuria with shorter time, higher accuracy, and higher throughput, thus allowing earlier pathogen-adapted antibiotic therapy for patients.