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Chris Mathes

Publications and source records attributed to Chris Mathes.

4 recordsLinked to original sources
PubMed2007

CRACking ion channel targets: 2nd annual Ion Channel Targets Conference. 12-13 September 2006, Boston, MA, USA.

The 2nd Annual Ion Channel Targets (ICT) Conference (by Select Bioscience LLC) was held in Boston on 12-13 September 2006. A healthy mixture of scientists from pharma, biotech and academic sectors attended the meeting. The speaker list reflected this mixture. In general, the conference focused on new ion channel targets and the methods for studying them in detail. Keynote lectures from Professors David Clapham (Harvard Medical School, USA) and Reinhold Penner (University of Hawaii, USA) set the tone by highlighting recent findings with a voltage-gated proton channel (Clapham), cation channel in sperm (Clapham) and the calcium-release-activated calcium channel (Penner). Also described at ICT were voltage-gated sodium, potassium, transmembrane-receptor-potential channels, as well as ligand-gated nicotinic acetylcholine (nAChR) and GABA type A receptors.

Animals↗
PubMed2006

QPatch: the past, present and future of automated patch clamp.

The QPatch 16 significantly increases throughput for gigaseal patch clamp experiments, making direct measurements in ion channel drug discovery and safety testing feasible. Released to the market in the Autumn of 2004 by Sophion Bioscience, the QPatch originated from work done at NeuroSearch (Denmark) in the early days of automated patch clamp. Today, the QPatch provides many unique features. For example, only the QPatch includes an automated cell preparation station making several hours of unattended operation possible. The 16-channel electrode array, called the QPlate, includes glass-coated microfluidic channels for less compound absorption and, hence, more accurate IC(50) values. The microfluidic pathways also allow for very small amounts of compound used for each experiment ( approximately 5 microl per addition). Only the QPatch has four independent pipetting heads for more efficient liquid handling (especially for ligand-gated ion channel experiments). Patch clamp recordings with the QPatch match the high quality of conventional patch clamp and in some cases the results are even better. For example, only the QPatch includes 100% series resistance compensation for the elimination of false positives due to voltage errors. Finally, the modular QPatch 16 was designed with more channels in mind. The upgrade pathway to 48-channels (the QPatch HT) will be discussed.

Animals↗
PubMed2005

Identifying modulators of hERG channel activity using the PatchXpress planar patch clamp.

The authors used the PatchXpress 7000A system to measure compound activity at the hERG channel using procedures that mimicked the "gold-standard" conventional whole-cell patch clamp. A set of 70 compounds, including hERG antagonists with potencies spanning 3 orders of magnitude, were tested on hERG302-HEK cells using protocols aimed at either identifying compound activity at a single concentration or obtaining compound potency from a cumulative concentration dependence paradigm. After exposure to compounds and subsequent washout of the wells to determine reversibility of the block, blockade by a reference compound served as a quality control. Electrical parameters and voltage dependence were similar to those obtained using a conventional whole-cell patch clamp. Rank order of compound potency was also comparable to that determined by conventional methods. One exception was flunarizine, a particularly lipophilic compound. The PatchXpress accurately identified the activity of 29 moderately potent antagonists, which only weakly displace radiolabeled astemizole and are false negatives in the binding assay. Finally, no false hits were observed from a collection of relatively inactive compounds. High-quality data acquisition by PatchXpress should help accelerate secondary screening for ion channel modulators and the drug discovery process.

Cell Line↗