Document Detail

A pressure-polishing set-up to fabricate patch pipettes that seal on virtually any membrane, yielding low access resistance and efficient intracellular perfusion.
MedLine Citation:
PMID:  21761372     Owner:  NLM     Status:  Publisher    
When performing whole-cell configuration recordings, it is important to minimize series resistance to reduce the time constant of charging the cell membrane capacitance and to reduce error in membrane potential control. To this end, an existing method was improved by widening the patch pipette shank through the calibrated combination of heat and air pressure. The heat was produced by passing current through a filament that was shaped appropriately to ensure a homogeneous heating of the pipette shank. Pressurized air was applied to the lumen of a pipette, pulled from a borosilicate glass microcap, via the pressure port of a modified commercial holder. The pipette reshaping was viewed on an LCD monitor connected to a contrast-intensified CCD camera and coupled to a modified bright-field stereomicroscope. By appropriately regulating the timing of air pressure and the application of heating, the pipette shank and, independently, the tip opening diameter were widened as desired. The methods illustrated here to fabricate and use the patch pipettes, using just one glass type, allowed the sealing of a wide variety of cell types isolated from different amphibian, reptilian, fish, and mammalian tissues as well as a variety of artificial membranes made with many different lipid mixtures. The access resistance yielded by pressure-polished pipettes was approximately one-fourth the size of the one attained with conventional pipettes; besides improving the electrical recordings, this minimized intracellular ion accumulation or depletion as well. Enlarged shank geometry allowed for fast intracellular perfusion as shown by fluorescence imaging, also via pulled quartz or plastic tubes, which could be inserted very close to the pipette tip.
Mascia Benedusi; Marco Aquila; Alberto Milani; Giorgio Rispoli
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-7-15
Journal Detail:
Title:  European biophysics journal : EBJ     Volume:  -     ISSN:  1432-1017     ISO Abbreviation:  -     Publication Date:  2011 Jul 
Date Detail:
Created Date:  2011-7-15     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8409413     Medline TA:  Eur Biophys J     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Dipartimento di Biologia ed Evoluzione, Sezione di Fisiologia e Biofisica, Università di Ferrara, Via L. Borsari 46, 44100, Ferrara, Italy.
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