A cell viability assessment method based on area-normalized impedance spectrum (ANIS)

Area of Science:

• Cell biology
• Biophysics
• Biosensing technology

Background:

• Electric cell-substrate impedance sensing (ECIS) is a standard technique for evaluating cell health.
• ECIS is susceptible to frequency drifts influenced by culture conditions and circuit models.
• Existing methods require improvements in stability and accuracy for reliable cell status assessment.

Purpose of the Study:

• To introduce and validate the area-normalized impedance spectrum (ANIS) method for enhanced cell viability assessment.
• To address the limitations of frequency drift and measurement noise in ECIS.
• To demonstrate the superior stability and accuracy of ANIS over conventional impedance sensing.

Main Methods:

• Developed the ANIS method, normalizing impedance spectrum area within a threshold (Zth) defined by a 2% impedance decline.
• Compared the stability of ANIS and conventional impedance sensing by normalizing area and impedance.
• Validated ANIS using Cell Count Kit-8 (CCK-8) assay and analyzed noise susceptibility.

Main Results:

• ANIS exhibited smoother, less fluctuating normalized area compared to the wave-like normalized impedance.
• ANIS showed a 2.4% increase in correlation index and a 4% decrease in maximum error versus the impedance sensing method.
• ANIS demonstrated reduced sensitivity to random measurement noise compared to traditional ECIS.

Conclusions:

• The ANIS method provides a more stable and accurate approach for assessing cell viability.
• ANIS overcomes the limitations of frequency drift and measurement noise inherent in standard ECIS.
• This novel method enhances the reliability of cell status monitoring in various biological applications.