TY  - JOUR
A1  - Klamp, Tobias
A1  - Camps, Marta
A1  - Nieto, Benjamin
A1  - Guasch, Francesc
A1  - Ranasinghe, Rohan T.
A1  - Wiedemann, Jens
A1  - Petrášek, Zdeněk
A1  - Schwille, Petra
A1  - Klenerman, David
A1  - Sauer, Markus
T1  - Highly Rapid Amplification-Free and Quantitative DNA Imaging Assay
JF  - Scientific Reports
N2  - There is an urgent need for rapid and highly sensitive detection of pathogen-derivedDNAin a point-of-care (POC) device for diagnostics in hospitals and clinics. This device needs to work in a ‘sample-in-result-out’ mode with minimum number of steps so that it can be completely integrated into a cheap and simple instrument. We have developed a method that directly detects unamplified DNA, and demonstrate its sensitivity on realistically sized 5 kbp targetDNA fragments of Micrococcus luteus in small sample volumes of 20 mL. The assay consists of capturing and accumulating of target DNA on magnetic beads with specific capture oligonucleotides, hybridization of complementary fluorescently labeled detection oligonucleotides, and fluorescence imaging on a miniaturized wide-field fluorescence microscope. Our simple method delivers results in less than 20 minutes with a limit of detection (LOD) of,5 pMand a linear detection range spanning three orders of magnitude.
KW  - laboratory techniques and procedures
KW  - diseases
KW  - infectious diseases
KW  - assay systems
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130500
VL  - 3
IS  - 1852
ER  - 
TY  - JOUR
A1  - Kohlmorgen, Britta
A1  - Elias, Johannes
A1  - Schoen, Christoph
T1  - Improved performance of the artus Mycobacterium tuberculosis RG PCR kit in a low incidence setting: a retrospective monocentric study
JF  - Scientific Reports
N2  - Tuberculosis (TB) and the spread of Mycobacterium tuberculosis complex (MTBC) strains resistant against rifampin (RIF) and isoniazid (INH) pose a serious threat to global health. However, rapid and reliable MTBC detection along with RIF/INH susceptibility testing are challenging in low prevalence countries due to the higher rate of false positives. Here, we provide the first performance data for the artus MTBC PCR assay in a low prevalence setting. We analyze 1323 respiratory and 311 non-respiratory samples with the artus MTBC PCR assay as well as by mycobacterial culture and microscopy. We propose retesting of specimens in duplicate and consideration of a determined cycle-threshold value cut-off greater than 34, as this significantly increases accuracy, specificity, and negative predictive value without affecting sensitivity. Furthermore, we tested fourteen MTBC positive samples with the GenoType MTBDRplus test and demonstrate that using an identical DNA extraction protocol for both assays does not impair downstream genotypic testing for RIF and INH susceptibility. In conclusion, our procedure optimizes the use of the artus MTB assay with workload efficient methods in a low incidence setting. Combining the modified artus MTB with the GenoType MTBDRplus assays allows rapid and accurate detection of MTBC and RIF/INH resistance.
KW  - laboratory techniques and procedures
KW  - Tuberculosis
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159248
VL  - 7
IS  - 14127
ER  -