The voltage clamp is an experimental method used by electrophysiologists to measure the ion currents through the membranes of excitable cells, such as neurons while holding the membrane voltage at a set level. A basic voltage-clamp will iteratively measure the membrane potential, and then change the membrane potential (voltage) to the desired value by adding the necessary current. This "clamps" the cell membrane at a desired constant voltage, allowing the voltage clamp to record what currents are delivered. Because the currents applied to the cell must be equal to (and opposite in charge to) the current going across the cell membrane at the set voltage, the recorded currents indicate how the cell reacts to changes in membrane potential. Cell membranes of excitable cells contain many different kinds of ion channels, some of which are voltage-gated. The voltage clamp allows the membrane voltage to be manipulated independently of the ionic currents, allowing the current-voltage relationships of membrane channels to be studied.

1. Voltage Clamp and Patch
Clamp Technique
4th November, 2019
Presented by,
Shryli K S
Vth Semester
Molecular Biology
Guided by,
Ms Sanjana Shajan
Dept. of Molecular Biology
Yuvaraja’s College (Autonomous)
Mysuru

2. Contents
• Introduction
• History
• Instrumentation and working of Voltage Clamp
technique
• Types of Voltage Clamp Technique
• Patch Clamp Technique
• Instrumentation and working of Patch Clamp
technique
• Types of Patch Clamp Technique
• Conclusion
• References
• Acknowledgement
6/14/2021
Voltage Clamp & Patch Clamp
Technique
2

3. Introduction
• Voltage Clamp technique is an
electrophysiological technique used to
record currents in biological memberanes.
• Excitable cells such as neuron, cardiac
cells, muscle cells etc.
6/14/2021
Voltage Clamp & Patch Clamp
Technique
3

4. History
• Hodgkin & Huxley.
1952.
• Revealed the action
potential event.
• Nobel prize, 1963
• Kenneth Cole and George
Mormont. 1947.
• Squid axon.
6/14/2021
Voltage Clamp & Patch Clamp
Technique
4

5. Instrumentation & Working
6/14/2021
Voltage Clamp & Patch Clamp
Technique
5

6. Example
6/14/2021
Voltage Clamp & Patch Clamp
Technique
6

7. 6/14/2021 Voltage Clamp & Patch Clamp Technique 7

8. Types
• Axial wire technique
• Gap method
• Suction pipette
method
• Two electrode
voltage clamp
• Dual cell voltage
clamp
• Single electrode
voltage clamp
6/14/2021
Voltage Clamp & Patch Clamp
Technique
8

9. Patch Clamp Technique
• It allows the recording of macroscopic
whole cell or microscopic single–channel
currents flowing across cell membrane.
6/14/2021
Voltage Clamp & Patch Clamp
Technique
9

10. History
• Nehar and Sakmann developed it. Late 1970’s.
• Nobel Prize in 1991.
• Determined single channel currents across a membrane
patch of a frogs skeletal muscle.
6/14/2021
Voltage Clamp & Patch Clamp
Technique
10

11. Instrumentation and Working
Voltage Clamp & Patch Clamp
Technique
11

12. Types
• Cell attached
• Whole cell patch
• Outside out patch
• Inside out patch
• Perforated patch
• Loose patch
6/14/2021
Voltage Clamp & Patch Clamp
Technique
12

13. Advantages
6/14/2021
Voltage Clamp & Patch Clamp
Technique
13

14. Conclusion
• It allows separation of membrane ionic
and capacitive current.
• It easier to obtain information with an
uniform voltage, than when the voltage is
changing.
6/14/2021
Voltage Clamp & Patch Clamp
Technique
14

15. References
• James V Halliwell, Tim D Plant, Jon Robbins, Nick B Standen;
Voltage Clamp Technique; 2016; 19pp
• Harvey M Fishman, Dept. of physiology & bioinformatics; Elsevier
North- Holland Scientific Publishers Ltd; 1982; 43pp
• Hans Reiner Polder, Martin Weskamp, Klaus Linz, Rainer Meyer;
Voltage-Clamp and Patch-Clamp Techniques; In-Vitro Techniques;
52pp
• Dirk L. Ypey & Louis J. DeFelice; The Patch- Clamp Technique
Explained and Exercised with the simple Electrical Equivalent
Circuits; 55pp
• https://en.wikipedia.org/wiki/Voltage_clamp
• www.youtube.com
6/14/2021
Voltage Clamp & Patch Clamp
Technique
15

16. Acknowledgement
I thank the department of Molecular Biology
for providing me this opportunity to present
my seminar, I express my sincere gratitude
to Ms Sanjana Shajan for her continuous
support and encouragement.
Thank you all for your patience :)
6/14/2021
Voltage Clamp & Patch Clamp
Technique
16