Few data are available concerning single Ca channel properties in inner ear hair cells, and particularly none in vestibular type I hair cells. By using the cell-attached configuration of the patch-clamp technique in combination with the semicircular canal crista slice preparation, we determined the elementary properties of voltage-dependent Ca channels in chicken embryo type I and type II hair ...

It is clear from the equations that each atom of oxygen in solution finally liberates one molecule of iodine. The iodine is titrated against sodium thiosulphate solution using starch as indicator; 1 c.c. of normal sodium thiosulphate solution corresponds to 8 mg. of oxygen, or 5-6 c.c. of oxygen at N.T.P. A number of modifications of the original technique of Winkler has been described. The acc...

Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manu...

We have implemented a simple, inexpensive, and fast procedure for validation and verification of the performance of pipettes mounted on automated liquid handlers (ALHs) as necessary for laboratories accredited under ISO 17025. A six- or seven-step serial dilution of OrangeG was prepared in quadruplicates in a flat-bottom 96-well microtiter plate, manually using calibrated pipettes. Each pipette...

We have used ion-selective electrodes (ISEs) to quantify ion fluxes across giant membrane patches by measuring and simulating ion gradients on both membrane sides. Experimental conditions are selected with low concentrations of the ions detected on the membrane side being monitored. For detection from the cytoplasmic (bath) side, the patch pipette is oscillated laterally in front of an ISE. For...

Nanometer-sized glass and quartz pipettes have been widely used as a core of chemical sensors, patch clamps, and scanning probe microscope tips. Many of those applications require the control of the surface charge and chemical state of the inner pipette wall. Both objectives can be attained by coating the inner wall of a quartz pipette with a nanometer-thick layer of carbon. In this letter, we ...

Few data are available concerning single Ca channel properties in inner ear hair cells and particularly none in vestibular type I hair cells. By using the cell-attached configuration of the patch-clamp technique in combination with the semicircular canal crista slice preparation, we determined the elementary properties of voltage-dependent Ca channels in chicken embryo type I and type II hair c...

The effect of focal mechanical stress on the localization of TRPV2 was investigated in HT1080 cells, where only mRNA for TRPV2 was detected among members of the TRPV channel family. Mechanical stress was applied by adding negative pressure using a glass pipette. When focal mechanical stress was applied, subplasma membrane Ca(2+) concentration ([Ca(2+)]s) was increased beneath the pipette, which...

Micropipette aspiration measures the mechanical properties of single cells. A traditional micropipette aspiration system requires a bulky infrastructure and has a low throughput and limited potential for automation. We have developed a simple microfluidic device which is able to trap and apply pressure to single cells in designated aspiration arrays. By changing the volume flow rate using a syr...