QuantuMDx (United Kingdom)

Jonte Hance says that the recent increase in tuition fees will only delay the inevitable fall of the UK academic system.

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To achieve the global efforts to end tuberculosis, affordable diagnostics suitable for true point-of-care implementation are required to reach the missing millions. In addition, diagnostics with increased sensitivity and expanded drug susceptibility testing are needed to address drug resistance and to diagnose low-bacterial burden cases. The laboratory-on-a-chip technology described herein used dielectrophoresis to selectively isolate Mycobacterium tuberculosis from sputum samples, purifying the bacterial population ahead of molecular confirmation by multiplex real-time quantitative PCR. After optimization using a panel of 50 characterized sputum samples, the performance of the prototype was assessed against the current gold standards, screening 100 blinded sputum samples using characterized and biobanked sputum provided by Foundation for Innovative New Diagnostics. Concordance with culture diagnosis was 100% for smear-negative samples and 87% for smear-positive samples. Of the smear-positive samples, the high burden sample concordance was 100%. Samples were diagnosed on the basis of visual assessment of the dielectrophoresis array and by multiplex real-time quantitative PCR assay. The results described herein demonstrate the potential of the CAPTURE-XT technology to provide a powerful sample preparation tool that could function as a front-end platform for molecular detection. This versatile tool could equally be applied as a visual detection diagnostic, potentially associated with bacterial identification for low-cost screening or coupled with an expanded PCR assay for genotypic drug susceptibility testing.

Additive manufacturing for microfluidics shows potential to boost research and development in research biology and molecular diagnostics. This paper reports on novel process and material optimisation techniques in the creation of a monolithic microfluidic chip geometry for polymerase chain reaction (PCR) thermocycling using stereolithography (SLA). A two-stage printing protocol with projection SLA is assessed in printing disposable oscillating-flow microfluidic cartridges for PCR. Print performance was characterized in terms of critical channel dimensions and surface quality. Post-treatment with ultraviolet light and solvent washes was shown to reduce PCR inhibiting residuals and facilitate the reaction, indicating material compatibility for fluidic and milli-fluidic PCR architectures. Residuals leaching from the polymer were shown via quantitative PCR that interact with enzyme activity. Passivation of channel surfaces with a polyethylene glycol and a silane static coating reduced the leaching interface improving overall PCR efficiency. The discussed protocols can serve as a low-cost alternative to clean-room and micromachined microfluidic prototypes for various microfluidic concepts.

The aim of this study was to assess pathogen DNA extraction with a new spin column-based method (DNA-XT). DNA from either whole-blood samples spiked with Plasmodium falciparum or Leishmania donovani amastigote culture was extracted with DNA-XT and compared with that produced by a commercial extraction kit (DNeasy®). Eluates from large and small sample volumes were assessed by PCR and spectroscopy. Using a small volume (5 μl) of blood, the DNA-XT and DNeasy methods produced eluates with similar DNA concentrations (0.63 vs 1.06 ng/μl, respectively). The DNA-XT method produced DNA with lower PCR inhibition than DNeasy. The new technique was also twice as fast and required fewer plastics and manipulations but had reduced total recovered DNA compared with DNeasy.

BackgroundPoint of care (POC) testing for infectious diseases can provide actionable diagnostic information as soon as individuals present to healthcare systems. POC testing for sexually transmitted infections could have a significant impact on sexual health by enabling screening programs, reducing loss to follow-up and enabling immediate and targeted treatment. We have developed a novel rapid real-time PCR assay which can detect Chlamydia trachomatis in clinical samples.MethodsDNA was extracted from 122 residual genital swab and urine samples previously tested in the Roche cobas CT/NG assay using the Qiagen DNA mini kit and the DNA extracts were tested for C. trachomatis using the rapid real-time PCR assay.ResultsOf the 122 samples, forty were negative in both the new rapid real-time PCR assay and the Roche cobas assay; 78 samples were positive in both assays and four samples were positive in the cobas assay but negative in the new novel assay. The specificity of the new novel assay was 100% and its sensitivity was 95.1% respectively. The four samples which were negative in the new assay had high Ct values in the cobas test indicating low levels of chlamydia organisms were present in the samples.ConclusionThe rapid real-time PCR system is rapid, sensitive and specific for the detection of C. trachomatis in clinical samples from patients with chlamydia infection. The rapid real-time PCR assay for C. trachomatis forms the basis for a low cost, disposable sample to answer diagnostic assay cassette, which will run on the QuantuMDx Q-POC™ platform.DisclosureNo significant relationships.