Swiss quality

Do you accept poor quality in ion channel screening?


For establishment of Structure Activity Relationship (SAR) and reliable anticipation of preclinical and clinical studies, High Quality Criteria in Ion Channel Screening are essential.


bSys Quality Standards

We defined 9 criteria in ion channel screening that remain equally valid for large and small compound batches:

  1. Current Amplitude large enough (>500 pA for hERG, mean of 1000 cells: 1.15 nA) (see fig. 1a,d)
  2. Rundown <10% over entire measurement, no “rundown correction” needed (see fig. 1a-c)
  3. Seal resistance >1 GΩ, no leak subtraction needed
  4. Series resistance stable and controlled (see fig. 1c)
  5. True steady state values evaluated after complete wash in (see fig. 2a,b)
  6. Reference substances: dose response curves match literature data (see fig. 2c)
  7. Full glass equipment avoids underestimated IC50 values of sticky compounds
  8. Small error bars due to low dispersion of values (see fig. 2c)
  9. Reproducibility also in non-GLP screens and studies

What it should look like in hERG Screening

Fig. 1

ab

cd

⇒ High current amplitudes throughout experiment time course - rundown<10%, stableseries resistance.
⇒ Mean current amplitude of the last 1000 cells (1.15 nA).

Fig. 2

ab

c  

⇒ Example of test item application (Terfenadine)

⇒ Interested in high quality? Please contact us: assay@bsys.ch or www.bsys.ch