Bammesberger S.B.,Albert Ludwigs University of Freiburg |
Malki I.,Albert Ludwigs University of Freiburg |
Ernst A.,Albert Ludwigs University of Freiburg |
Ernst A.,BioFluidix GmbH |
And 4 more authors.
Journal of Laboratory Automation | Year: 2014
We present a noncontact liquid dispenser that uses a disposable cartridge for the calibration-free dosage of diverse biochemical reagents from the nanoliter to the microliter range. The dispensing system combines the advantages of a positive displacement syringe pump (responsible for defining the aliquot’s volume with high accuracy) with a highly dynamic noncontact dispenser (providing kinetic energy to detach the liquid from the tip). The disposable, noncontact dispensing cartridge system renders elaborate washing procedures of tips obsolete. A noncontact sensor monitors the dispensing process to enable an online process control. To further increase confidence and reliability for particularly critical biomedical applications, an optional closed-loop control prevents malfunctions. The dispensing performance was characterized experimentally in the range of 0.25 to 10.0 µL using liquids of different rheological properties (viscosity 1.03–16.98 mPas, surface tension 30.49–70.83 mN/m) without adjusting or calibrating the actuation parameters. The precision ranged between a coefficient of variation of 0.5% and 5.3%, and the accuracy was below ±10%. The presented technology has the potential to contribute significantly to the improvement of biochemical liquid handling for laboratory automation in terms of usability, miniaturization, cost reduction, and safety. © 2013 Society for Laboratory Automation and Screening.
Rombach M.,Hsg Imitinstitut For Mikro Und Informationstechnik |
Rombach M.,Albert Ludwigs University of Freiburg |
Kosse D.,Hsg Imitinstitut For Mikro Und Informationstechnik |
Faltin B.,Albert Ludwigs University of Freiburg |
And 7 more authors.
BioTechniques | Year: 2014
A method for conserving primers and differently labeled fluorogenic hydrolysis (i.e., TaqMan) probes at ambient conditions is presented. Primers and hydrolysis probes with four different fluorophore-quencher combinations (6- FAM–BHQ1, HEX–BHQ1, ROX–BHQ650, and Cy5–BHQ2) were mixed with trehalose and xanthan at final concentrations of 56 mM and 2.78 mM, respectively. Mixtures were air-dried at 23°C for 30 min on strips composed of cyclo olefin polymer (COP), a material widely used in the manufacturing of in vitro diagnostic (IVD) test carriers. After one year of storage, the functionality of the primers and fluorophore-quencher combinations was validated by real-time polymerase chain reaction (real-time PCR), confirming their stability when stored in the presence of stabilizers, with the best results achieved using trehalose. This approach could be of great benefit for manufacturing IVD systems, for example, for genotyping applications based on multiplexing using different fluorescent dyes. © 2014, Eaton Publishing Company. All rights reserved.