Panning transfected cells for electrophysiological studies

Area of Science:

• Molecular Biology
• Cell Biology
• Biophysics

Background:

• Co-transfection is crucial for studying ion channel function.
• Selecting successfully co-transfected cells, especially for rare events, remains challenging.
• Existing methods lack efficiency in enriching for specific co-transfected cell populations.

Purpose of the Study:

• To develop and validate a novel cell panning technique for selecting co-transfected cells expressing ion channels.
• To enhance the efficiency of isolating cells for electrophysiological studies.
• To improve the yield of positively transfected cells for molecular and biophysical analysis.

Main Methods:

• Cells were co-transfected with ion channel and cell surface marker (CD8) plasmids using the CaPO4 method.
• Biotinylated anti-CD8 antibody and streptavidin-coated dishes were used for cell panning.
• High molar ratios of ion channel to CD8 plasmid (> or = 8:1) were employed.
• Selected cells were validated using whole-cell, perforated-patch, and single-channel recordings.
• Beta-galactosidase co-selection was used to quantify panning efficiency via histological assay.

Main Results:

• Panning increased the percentage of positively co-transfected cells by over 20-fold in some cases.
• Over 50% of adhered cells were positive for the co-selected gene when using optimal plasmid ratios.
• The technique proved effective even in poorly transfecting cell lines like NIH3T3.
• Successful selection of cells expressing voltage-dependent sodium channels and cystic fibrosis transregulator chloride channels was demonstrated.

Conclusions:

• Cell panning is a highly effective method for selecting co-transfected cells expressing specific genes, including ion channels.
• This technique significantly improves the enrichment of target cells for downstream applications like electrophysiology.
• The developed panning strategy offers a valuable tool for researchers working with transfection and cellular assays.