Comparison of manual and automated nucleic acid extraction methods from clinical specimens for microbial diagnosis purposes

BLADE-R: streamlined RNA extraction for molecular diagnostics and high-throughput applications

Efficient nucleic acid extraction and purification are crucial for cellular and molecular biology research, yet they pose challenges for large-scale clinical RNA sequencing and PCR assays. Here, we present BLADE-R, a magnetic bead-based protocol that simplifies the process by combining cellular lysis and nucleic acid binding into a single step, followed by a unique on-bead rinse for nuclease-free separation of genomic DNA and RNA. The Agilent TapeStation and RT-qPCR analyses show that RNA extracted from HEK293T cell line using BLADE-R outperforms the TRIzol protocol in terms of time and cost. RNA sequencing reveals no differences in sequence quality or gene count variance between samples processed with BLADE-R and those processed with TRIzol followed by RNA kit clean-up. Additionally, BLADE-R outperformed TRIzol in RNA extraction from frozen tissue and whole blood samples, as confirmed by RT-qPCR. Our protocol can be adapted to a 96-well plate format, enabling RNA purification of up to 96 human blood samples in less time than a single-sample traditional extraction. Using BLADE-R in this format, we confirmed minimal well-to-well contamination in RNA purification, cDNA synthesis, and PCR. Therefore, our novel BLADE-R protocol, suitable for both low and high-throughput formats, is effective even in limited-resource settings for preparing clinical samples for PCR and sequencing assays. Thus, our new BLADE-R technique works well even in low-resource environments to prepare clinical samples for PCR and sequencing experiments. It can be adapted for both low- and high-throughput formats.

The Role of the Biosafety Cabinet in Preventing Infection in the Clinical Laboratory

Clinical laboratories are essential in healthcare to better diagnose, treat, and track medical diseases. However, handling infectious organisms and possibly infectious materials in these laboratories puts the safety of laboratory workers and the general public at risk. By controlling the distribution of infectious substances and stopping the spread of diseases, biosafety cabinets (BSCs) have become crucial tools in guaranteeing laboratory safety. The prevention of infections is most important in medical and laboratory settings. In clinical laboratories, biological and infectious agents are handled, posing threats to healthcare workers and the general public. To avoid infections, proper training of the BSC is essential. Laboratory employees are instructed in aseptic procedures, proper hand posture, and efficient personal protection when working in the cabinet. These instructions decrease the chance of contaminating the surrounding area. Additionally, user ergonomics are taken into account while designing BSC, reducing operator fatigue, and guaranteeing that staff can execute tasks precisely for extended periods. This review highlights the importance of biosafety cabinets in maintaining a secure laboratory environment and explains their crucial function in infection control.

Toscana, West Nile, Usutu and tick-borne encephalitis viruses: external quality assessment for molecular detection of emerging neurotropic viruses in Europe, 2017

BackgroundNeurotropic arboviruses are increasingly recognised as causative agents of neurological disease in Europe but underdiagnosis is still suspected. Capability for accurate diagnosis is a prerequisite for adequate clinical and public health response.AimTo improve diagnostic capability in EVD-LabNet laboratories, we organised an external quality assessment (EQA) focusing on molecular detection of Toscana (TOSV), Usutu (USUV), West Nile (WNV) and tick-borne encephalitis viruses (TBEV).MethodsSixty-nine laboratories were invited. The EQA panel included two WNV RNA-positive samples (lineages 1 and 2), two TOSV RNA-positive samples (lineages A and B), one TBEV RNA-positive sample (Western subtype), one USUV RNA-positive sample and four negative samples. The EQA focused on overall capability rather than sensitivity of the used techniques. Only detection of one, clinically relevant, concentration per virus species and lineage was assessed.ResultsThe final EQA analysis included 51 laboratories from 35 countries; 44 of these laboratories were from 28 of 31 countries in the European Union/European Economic Area (EU/EEA). USUV diagnostic capability was lowest (28 laboratories in 18 countries), WNV detection capacity was highest (48 laboratories in 32 countries). Twenty-five laboratories were able to test the whole EQA panel, of which only 11 provided completely correct results. The highest scores were observed for WNV and TOSV (92%), followed by TBEV (86%) and USUV (75%).ConclusionWe observed wide variety in extraction methods and RT-PCR tests, showing a profound absence of standardisation across European laboratories. Overall, the results were not satisfactory; capacity and capability need to be improved in 40 laboratories.

Automation of RNA-based biomarker extraction from dried blood spots for the detection of blood doping

Aim: Transcriptomic biomarkers originating from reticulocytes measured in dried blood spots (DBSs) may be reliable indicators of blood doping. Methods/results: Here, we examined changes in the expression levels of the erythropoiesis-related ALAS2, CA1 and SLC4A1 genes in DBS samples from elite athletes and volunteers of clinical study with recombinant erythropoietin dose. Conclusion: By comparing the mean intraday coefficients of variation for ALAS2L, ALASLC, CA1 and SLC4A1 between manual and automated RNA extractions, an average improvement was observed, whereas the assessment of interday variability provided comparable results for both manual and automated approaches. Our results confirmed that RNA biomarkers on DBS support are efficient to detect blood doping.

Equipment-free nucleic acid extraction and amplification on a simple paper disc for point-of-care diagnosis of rotavirus A

The use of paper-based methods for clinical diagnostics is a rapidly expanding research topic attracting a great deal of interest. Some groups have attempted to realize an integrated nucleic acid test on a single microfluidic paper chip, including extraction, amplification, and readout functions. However, these studies were not able to overcome complex modification and fabrication requirements, long turn-around times, or the need for sophisticated equipment like pumps, thermal cyclers, or centrifuges. Here, we report an extremely simple paper-based test for the point-of-care diagnosis of rotavirus A, one of the most common pathogens that causes pediatric gastroenteritis. This paper-based test could perform nucleic acid extraction within 5 min, then took 25 min to amplify the target sequence, and the result was visible to the naked eye immediately afterward or quantitative by the UV-Vis absorbance. This low-cost method does not require extra equipment and is easy to use either in a lab or at the point-of-care. The detection limit for rotavirus A was found to be 1 × 10³ copies/mL. In addition, 100% sensitivity and specificity were achieved when testing 48 clinical stool samples. In conclusion, the present paper-based test fulfills the main requirements for a point-of-care diagnostic tool, and has the potential to be applied to disease prevention, control, and precision diagnosis.