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Topic: EDTA and magnesium chloride  (Read 17368 times)

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Offline Borek

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EDTA and magnesium chloride
« on: June 07, 2005, 04:49:40 AM »
What is their use in biochemical experiments?
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Offline Mitch

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Re:EDTA and magnesium chloride
« Reply #1 on: June 08, 2005, 08:39:49 AM »
EDTA is used to titrate metals in Chemistry.
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Offline Borek

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Re:EDTA and magnesium chloride
« Reply #2 on: June 08, 2005, 08:53:49 AM »
What is EDTA used for in analytical chemistry I know :P However browsing the web in recipes for the solutions used in biochemistry experiments I often see buffers plus EDTA plus magnesium chloride. Buffer use is obvious, but what role plays MgCl2? And why is magnesium chelated with EDTA?

Same problem, additional question: sometimes succrose is used in high concentrations. Is it used just to obtain high viscosity, or something else?
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savoy7

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Re:EDTA and magnesium chloride
« Reply #3 on: June 09, 2005, 12:43:35 AM »
NOTE:  not best answer - just from the top of my head - you should probably research more -

this is really simplified
Basics -
Mg ions can "activate" some enzymes

EDTA - chelates - picks up Mg ions

Assays - depends on what you are doing - isolating DNA, cutting it, ligating it. copying it, etc
so - you want to store DNA - it is usually done in a buffer with EDTA - one would not want enzymes to break down DNA

Now you want to "cut" the DNA - you might need Mg to "activate" the enzyme, so you have to added Mg - note it is usually more because it has to conpensate for the EDTA the DNA was stored in

Offline lemonoman

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Re:EDTA and magnesium chloride
« Reply #4 on: July 04, 2005, 03:52:41 PM »
I am told that,

"So basically um, when you do a reaction Mg2+ is used as energy in an experiment, like PCR (polymerase chain reacction).  So in order to stop the reaction, you add EDTA which complexes the Mg2+ so you don't have any energy to be used and stops the reaction"

Hope that helped.  It's a quote from a 'personal communication'...i.e. I asked my friend Mike

Offline Borek

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Re:EDTA and magnesium chloride
« Reply #5 on: July 04, 2005, 05:26:04 PM »
Mg2+ as a source of energy?

Are we talking about the same chemistry and the same periodic table?  ;)

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Offline lemonoman

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Re:EDTA and magnesium chloride
« Reply #6 on: July 04, 2005, 06:22:47 PM »
Don't worry.  I slapped Mike upside the head for that one.

I've never taken a biology course in my life.  And henceforth promise to stay out of this section of the forum...no matter who my friends proclaim to be.

Cheers!

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