Measurement of bioelectric current with a vibrating probe.

Brian Reid, Min Zhao

Research output: Contribution to journalArticle

Abstract

Electric fields, generated by active transport of ions, are present in many biological systems and often serve important functions in tissues and organs. For example, they play an important role in directing cell migration during wound healing. Here we describe the manufacture and use of ultrasensitive vibrating probes for measuring extracellular electric currents. The probe is an insulated, sharpened metal wire with a small platinum-black tip (30-35 μm), which can detect ionic currents in the μA/cm(2) range in physiological saline. The probe is vibrated at about 200 Hz by a piezoelectric bender. In the presence of an ionic current, the probe detects a voltage difference between the extremes of its movement. A lock-in amplifier filters out extraneous noise by locking on to the probe's frequency of vibration. Data are recorded onto computer. The probe is calibrated at the start and end of experiments in appropriate saline, using a chamber which applies a current of exactly 1.5 μA/cm(2). We describe how to make the probes, set up the system and calibrate. We also demonstrate the technique of cornea measurement, and show some representative results from different specimens (cornea, skin, brain).

Original languageEnglish (US)
JournalJournal of visualized experiments : JoVE
Issue number47
StatePublished - 2011
Externally publishedYes

Fingerprint

Cornea
Ion Transport
Vibration
Platinum
Wound Healing
Cell Movement
Noise
Metals
Skin
Brain
Electric currents
Biological systems
Electric fields
Wire
Ions
Tissue
Electric potential
Experiments

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Measurement of bioelectric current with a vibrating probe. / Reid, Brian; Zhao, Min.

In: Journal of visualized experiments : JoVE, No. 47, 2011.

Research output: Contribution to journalArticle

@article{7117bc9c9ba548488e104cb9d454e7a9,
title = "Measurement of bioelectric current with a vibrating probe.",
abstract = "Electric fields, generated by active transport of ions, are present in many biological systems and often serve important functions in tissues and organs. For example, they play an important role in directing cell migration during wound healing. Here we describe the manufacture and use of ultrasensitive vibrating probes for measuring extracellular electric currents. The probe is an insulated, sharpened metal wire with a small platinum-black tip (30-35 μm), which can detect ionic currents in the μA/cm(2) range in physiological saline. The probe is vibrated at about 200 Hz by a piezoelectric bender. In the presence of an ionic current, the probe detects a voltage difference between the extremes of its movement. A lock-in amplifier filters out extraneous noise by locking on to the probe's frequency of vibration. Data are recorded onto computer. The probe is calibrated at the start and end of experiments in appropriate saline, using a chamber which applies a current of exactly 1.5 μA/cm(2). We describe how to make the probes, set up the system and calibrate. We also demonstrate the technique of cornea measurement, and show some representative results from different specimens (cornea, skin, brain).",
author = "Brian Reid and Min Zhao",
year = "2011",
language = "English (US)",
journal = "Journal of Visualized Experiments",
issn = "1940-087X",
publisher = "MYJoVE Corporation",
number = "47",

}

TY - JOUR

T1 - Measurement of bioelectric current with a vibrating probe.

AU - Reid, Brian

AU - Zhao, Min

PY - 2011

Y1 - 2011

N2 - Electric fields, generated by active transport of ions, are present in many biological systems and often serve important functions in tissues and organs. For example, they play an important role in directing cell migration during wound healing. Here we describe the manufacture and use of ultrasensitive vibrating probes for measuring extracellular electric currents. The probe is an insulated, sharpened metal wire with a small platinum-black tip (30-35 μm), which can detect ionic currents in the μA/cm(2) range in physiological saline. The probe is vibrated at about 200 Hz by a piezoelectric bender. In the presence of an ionic current, the probe detects a voltage difference between the extremes of its movement. A lock-in amplifier filters out extraneous noise by locking on to the probe's frequency of vibration. Data are recorded onto computer. The probe is calibrated at the start and end of experiments in appropriate saline, using a chamber which applies a current of exactly 1.5 μA/cm(2). We describe how to make the probes, set up the system and calibrate. We also demonstrate the technique of cornea measurement, and show some representative results from different specimens (cornea, skin, brain).

AB - Electric fields, generated by active transport of ions, are present in many biological systems and often serve important functions in tissues and organs. For example, they play an important role in directing cell migration during wound healing. Here we describe the manufacture and use of ultrasensitive vibrating probes for measuring extracellular electric currents. The probe is an insulated, sharpened metal wire with a small platinum-black tip (30-35 μm), which can detect ionic currents in the μA/cm(2) range in physiological saline. The probe is vibrated at about 200 Hz by a piezoelectric bender. In the presence of an ionic current, the probe detects a voltage difference between the extremes of its movement. A lock-in amplifier filters out extraneous noise by locking on to the probe's frequency of vibration. Data are recorded onto computer. The probe is calibrated at the start and end of experiments in appropriate saline, using a chamber which applies a current of exactly 1.5 μA/cm(2). We describe how to make the probes, set up the system and calibrate. We also demonstrate the technique of cornea measurement, and show some representative results from different specimens (cornea, skin, brain).

UR - http://www.scopus.com/inward/record.url?scp=84873022049&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84873022049&partnerID=8YFLogxK

M3 - Article

JO - Journal of Visualized Experiments

JF - Journal of Visualized Experiments

SN - 1940-087X

IS - 47

ER -