IV curve

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anja
anja's picture
IV curve

hi
Just started learning about the patch clamp technique, and have a question: why do one make a IV curve? And why does the water content in test solutions have to be under 1%?
thanks

Fraser Moss
Fraser Moss's picture
The IV curve gives the

The IV curve gives the current-voltage relationship.

This tells the investigator the "voltage-dependence" of the channel being investigated

The term IV curve usually refers to the current voltage relationship of channel activatoin, but you can also study the voltage-dependence of inactivation.

The relationship will usually be best fit with a suitable equation from which you will be able to determine the half maximal activation voltage (V50, or V1/2 - the voltage at which the current gated by the channel is 50% of the maximum current that it is able to gate) which is a more accurate way of expressing the channel's voltage dependence than the voltage at which the peak current occurs.

You should read the following

Patch Clamping: An Introductory Guide to Patch Clamp Electrophysiology
by Areles Molleman
John Wiley & Sons (December 20, 2002)
ISBN: 047148685X

http://www.amazon.com/Patch-Clamping-Introductory-Guide-Electrophysiology/dp/047148685X/sr=8-1/qid=1161018078/ref=pd_bbs_sr_1/102-0640616-8696128?ie=UTF8

and once you have digested that take the next step up to

Ion Channels of Excitable Membranes (3rd Edition)
by Bertil Hille
Sinauer Associates; 3rd edition (July 1, 2001)
ISBN: 0878933212

http://www.amazon.com/Ion-Channels-Excitable-Membranes-3rd/dp/0878933212/sr=8-2/qid=1161018078/ref=pd_bbs_sr_2/102-0640616-8696128?ie=UTF8

Also search "voltage dependence " and "ion channel" in pubmed and read papers about different channels ot get the idea what is going on.