Calcium influx detection |
Membrane potential assays |
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For voltage-gated calcium channel |
Utilize fluorescent dyes sensitive to membrane potential |
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Electrophysiology assays |
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HD Biosciences is equipped with state of the art manual patch-clamp technology. |
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Whole-cell recording in mammalian expression systems can be conducted to test the effects of drugs on voltage-gated (hERG channel). In order to increase throughput of patch-clamp analysis, HD Biosciences has DADVC-8PP: Pinch valve system for fast switching of perfusion solution. The application system can be easily mounted on already |
running patch clamp setups. |
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Patch clamp hERG safety testing services |
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hERG (human Ether-a-go-go-related gene, in italics, or KCNH2 in the new nomenclature) is a gene that encodes the pore-forming alpha subunit of a voltage-gated potassium channel expressed in the heart and in nervous tissue. The term hERG is often used to denote the protein or channel derived from the hERG transcript. In the heart hERG makes up a part, if not all, of the channel that conducts the ‘rapid’ component of the delayed rectifier |
current. |
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IKr is important in determining the timing of the electrical repolarization of the action potential (AP) in ventricular myocytes. Genetic mutation in the hERG channel can result in long QT syndrome (LQTS), a disorder in which the patient has a substantial risk of sudden death due to an arrhymia known Torsades de pointes (TdP). Typically, an LQTS patient will have no clinical signs expect prolongation of the QT interval on the electrocardiogram, and the patient will appear otherwise healthy, having no other symptoms expect some |
patients will suffer form occasional syncope. |
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hERG testing for drug candidates is a crucial element of drug development, as an estimated 25-40% of all lead compounds show some level of hERG related toxicity. HD Bio helps our clients solve hERG safety issues at early discovery stages and during preclinical |
development. |
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The HEK293-hERG cell line was generated at HD Biosciences. The cell line is currently |
being used by HD Bioscience's electrophysiology group. |
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Figure 1. High amplitudes of the hERG peak tail current throughout experiment time course - rundown<20%. |
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Figure 2. Measurement of hERG-inhibitory activity of quindine (C20H24N3O2) (literature IC50: 300-1000 nM). |
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(A) Cells were voltage-clamped at a holding potential of -80 mV, depolarized to +40 mV for 2000 ms, then clamped to -40 mV for 3000 ms, and last down to -80 mV to record tail |
current. The interpulse interval is 15 s. |
(B) Example traces of hERG currents recorded in the presence of increasing concentrations |
of quindine. |
(C) Time course of the hERG channel inhibition achieved by quindine for data shown in (B). Each dot represents the peak tail current amplitude measured in response to stimulation |
protocol described in (A). |
(D) The hill equation was fit to the data from the experiment. |