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What is it exactly that iodine does to cause the cell membranes of bacteria to rupture?

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Whenever an oxidizing agent acts upon an oxidizable substance, the oxidizing agent is itself reduced. Thus, iodine is reduced to iodide ion -- an electrolyte that upsets the cell's ion balance. This action will lead to the death of the bacterium in which the reaction occurs.

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Redox reactions are fun!

(The other halogens (chlorine, fluorine, bromine) also work, but are more likely to cause dangerous reactions in the human body. But that's why chlorine is used in swimming pools as an antiseptic agent.)


The redox reaction works on fungi too. However, iodine also has a specific chemical reaction with bacterial proteins (see here, under "halogens.")
 

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Posted by katharina (Member # 827) on :
 
So it is the acquired salty nature of the iodine, and not a poisoning mechanism from being a heavy metal.

Thank you!! I'm getting all sorts of new brain wrinkles today.

[ April 29, 2004, 02:51 PM: Message edited by: katharina ]
 

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Posted by Mike (Member # 55) on :
 
Just to clarify (I hope): iodine is neither a metal nor a salt. Though it is heavy. And it is a component of some salts, as iodide (a negative ion).
 

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Posted by katharina (Member # 827) on :
 
Yes, Mike. You're right. I did know that, but I expressed it sloppily.
 

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Posted by Mike (Member # 55) on :
 
Ah. Just making sure.

I'm curious: if they only had 70 grams to go, why didn't they jab you again? Did they decide your veins were too good at playing hide & seek?
 

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Posted by Yank (Member # 2514) on :
 
I just went to give blood plasma yesterday, and after about two ours of tests and general mucking about, they decided to reject me because I'm on Claritin for allergies (!). Oh well, I guess I got a free blood test.....

Anyway, I feel your pain.
 

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Posted by katharina (Member # 827) on :
 
I'm not sure. I think so. It took a long, long time and thorough examinatio of both arms to find the first one.
 

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Posted by rivka (Member # 4859) on :
 
I'm pretty sure (and Valentine, who used to stick people for a living, can confirm or deny this) that once they start a unit from one spot, they can't finish it off from another. Not sure exactly why.

Anyway, being a good clotter is useful in cases where you are injured -- less so when attempting to donate.
 

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Posted by katharina (Member # 827) on :
 
I should put that on my resume. "Good clotter"
 

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Posted by rivka (Member # 4859) on :
 
Or maybe, "Clots well under pressure."
 

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Posted by Valentine014 (Member # 5981) on :
 
Kat, they can stick you twice, but only under certain circumstances:

- only one stick per arm (this only goes for donating blood, not the vials they take during routine blood tests)
- only if there is another vein in the other arm that is worth trying (doesn't sound like this is the case)
- only if they took a very small amount of blood from you in the first arm (I can't remember the minimum amount, it changes, like many of the requirements do. I remember getting a new memo regarding new rules and exceptions at least once a week).

It's important that you try to prepare for your blood donation. A few hints to make your blood donation go a little smoother: make sure you have eaten that day, try to drink at least your 6-8 glasses of water that entire week prior to your donation, your veins will much happier if you do (as will your phelbotomist!) and understand that not everyone was meant to donate , it's possible that your veins will never be up it. The needle that is used is HUGE (16 gauge, don't look at it, some people get faint by just glancing at it) and must be, so that the red blood cells aren't damaged as they travel through it. Not all veins are large enough to accommodate it.

It's also possible that while the needle was being put in, a small hematoma, or bruise formed, slowing the blood to a trickle and finally clotting. It is quite common.

There are a million reason why this could've happened. I would recommend giving it one more try when you are eligible again and if the same thing happens, it might be best to stick to volunteering.

As I writing this, I noticed I assumed that you are donating blood for the first time but after skimming your post again, this might not be true. Have you ever donated? If so, have you ever had problems like this, or been a "slow bleed" during a donation?
 

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Posted by katharina (Member # 827) on :
 
This was only my second time giving blood. THe first time, they spent almost five minutes on my left arm, digging around with the needle trying to find the vein. After switching to the right arm, everything went smoothly. It's been a while since that time - I was a little skittish about it - so I can't say if anything's really changed. I haven't drunk as much water this week, for the terribly prosaic reason that I've been late to work all week, which means I park out in the boonies, which means I don't want to lug my case of water up three flights of stairs.

Thanks. That's all great to know. I love Hatrack!
 

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Posted by Lara (Member # 132) on :
 
Hey, that's a shame about the blood.

Okay, on the iodine thing, if anyone comes back to this- when I'm in the field for my job, we drop all our water with iodine. Eight drops per gallon, and I drink at least a gallon every day for eight days, so that's at least 64 iodine drops a shift. Sooo...what exactly is that doing to my insides?
 

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Posted by rivka (Member # 4859) on :
 
Making sure you don't get an iodine deficiency? Potential risks -- but I have no idea what constitutes too much iodine.
 

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