Ion Channel Screening Assays

Ion Channel Screening Assays

Aurora Biomed provides a wide range of ion channel assays to quickly and accurately provide results for drug discovery and development research worldwide. A convenient, integrated ordering system facilitates rapid assessment and processing of globally standardized tests. Assays are performed manually by patch clamp or by Qpatch. Cold flux assays are also available for limited compounds or candidates that cannot be screened with manual patch clamp, with a strong linear correlation (R=0.88) and consistently identical drug rank orders between the cold flux and patch clamp methods. Cold flux assays rely on non-radioactive trace ions measured by Aurora’s high-throughput atomic absorbance-based Ion Channel Reader series: ICR 8000 and ICR 12000

Electrophysiological in vitro and in vivo studies required by the FDA are available on either stable cell lines, cells transiently expressing channels of interest, transformed Xenopus oocytes (two-electrode voltage clamp), cardiac myocytes (freshly isolated from rat or guinea pig), or neurons differentiated from human iPS. Please contact info@iithai.com for more information.

The following Ion Channel Screening Assays are available from Aurora:

ApplicationIon ChannelIonic CurrentPatch ClampQPatch
Cardiac hERG/Kv11.1 IKr
Nav1.5 Peak, late INa
Kv1.5 IKur, Isus
Kv4.3/KChIP Ito
KCNQ1 (Kv7.1)/KCNE1 IKs
 
HCN2 If
HCN4 If
 
Kir2.1 IK1
 
Kir3.1/Kir3/4 IKACh
 
Kv1.4 IIto
 
Endogenous Cl  
 
 
CNS TRPV1 TRPV1
 
Nav1.2 INa
 
Nav1.6 INa
 
Nav1.7 INa
 
Kv1.2 Delayed rectifier
 
Kv2.1 Delayed rectifier
 
Kv3.1 Delayed rectifier
 
Kv3.2 Delayed rectifier
 
Kv4.2 IA
 
Stretch-activated K Delayed rectifier
 
 
HCN2 hyperpolarization-activated cyclic nucleotide-gated ion channel
 
 
Cav1.3 L type Ca channel
 
 
Cav1.4 L type Ca channel
 
 
Cav2.1 P/Q-type Ca channel
 
 
Cav2.2 N-type Ca channel
 
 
Cav2.3 R-type Ca channel
 
 
Cav3.1 T-type Ca channel
 
 
Cav3.3 T-type Ca channel
 
 
Co-transporters Na/K-ATPase antiporter enzyme / cotransporter
 
 
Na, K, Cl co-transporters cotransporter
 
 
Skeletal muscle Nav1.4 INa
 
Immune System Kv1.3 Delayed rectifier
 
Cold Flux available for all assays. Some also performed by Manual Patch Clamp or Qpatch as indicated.

Cardiac Myocyte Assays

Freshly isolated cardiac myocytes are collected from from rat or guinea pig. Parameters measured:

  • IC50 generated from dose-response curves at various frequencies
  • Use dependence, voltage-dependence of block
  • Custom-made protocols to address specific needs

Please contact info@iithai.com for more information.

Reliable, Reproducible Results

The robustness of Aurora Ion Channel Screening Assays is shown in the below figures. No matter the stage of drug discovery, obtaining quick and accurate results is key to any research assay.

IC50-of-flecainide

Figure 1: IC50 of flecainide for IhERG in CHO cells expressing hERG channels (Qpatch) and in HEK cells expressing hERG channels (manual patch clamp).

IC50-of-fecainide-HEK-Kv4-2

Figure 2: IKv4.2 block by flecainide in HEK cells expressing Kv4.2 channels by manual patch Clamp.

Mexiletene-and-late-inav1-5

Mexiletene-and-peak-late-inav1-5

Figure 3: The effects of mexiletine on peak and late INav1.5 measured by Qpatch (in the presence of the sea anemone toxin ATXII)

Scope of Screening Services

Typical test compound screening services are completed as follows, depending on research requirements. Raw data can be sent (without analysis) upon request.

Full Characterization
1 a. Full DR curve with 5-7 points, each averaged from at least 3 independent estimations, or; b. Results are fitted to the Hill equation for accurate estimation of IC50. If the coefficient of variability (SD/mean) exceeds 25% at IC50, up to 6 independent estimates are provided for the same price.
2 Effect of the compound (at ~IC50) on I-V and G-V curves, including fit to Boltzmann equation and estimate of any shifts in G-V curve.
3 Effect of the compound on the kinetics of voltage-dependent inactivation of the channel at 3 voltages.
Partial Characterization
1 DR curve with 4-5 points, each averaged from at least 3 independent estimations.
2 Effect of the compound (at IC50) on I-V curve.
Preliminary Characterization
1 a. Compound tested at a single dose in duplicate (n=2) at one voltage, or; b. Compound tested at two different doses at 3 voltages each (n=3).
Additional Characterization
1 Effect of the compound on steady-state inactivation curve.
2 For N-type Ca2+ channels, additional estimates of the effect of the compound on channel regulation by G proteins, including estimation of the change in the extent of voltage-dependent facilitation and/or inhibition by a G protein-coupled receptor.

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