6 replies to this topic

[Mummy]

Dear folks,

Being fairly new to the world of molecular biology, I would like to ask a tricky question from you: I want to learn more about the safety measures you use during acrylamide gel-pouring. Unfortunately our lab has no written rules, so I have seen wild things (people fingering the mixture with bare hands, etc.).
As far as I understand, One would have to work in lab coat, gloves (nitrile if possible - latex gets penetrated by acrylamide in a matter of minutes), and should not leave any acrylamide mess around (it will get absorbed through the skin if others touch it). I heard that the acrylic substances are pretty nasty, as the limit of no-adverse-effect (NOAEL) is below the 0.5 mg/day/kg level. And if neurotoxicity (risk of paralysis) would not be enough, its also a strong mutagen, causing cancer & translocation on chromosomes (risk of heritable genetic damage). And - if I could forget - ammonium persulfate (APS) and tetramethyl-methylene-diamine (TEMED) are kind of nasty, too! And...we tend to wash the equipments in regular tap water, reusing the pipette tips & tubes I guess that's not the best thing for the environment...

So I would welcome any advice I could use myself and spread to my colleagues as well!

Edited by Mummy, 10 August 2009 - 12:02 PM.

[bob1]

The biggest method of acrylamide poisoning is due to inhalation/ingestion. You are unlikely to see any adverse effects from touching it with bare hands in solution form - skin is pretty impenetrable to most things.  So long as you are not creating aerosols out of the solution when mixing or pouring the gels, you will be fine. The crosslinked/polymerised form is very stable and is non-toxic.
There was a case in New Zealand a few years ago where someone (allegedly) poisoned their former partner with acrylamide in their food. IIRC, it took quite some time for the effects to be seen, and even then the trial couldn't rule out that the victim wasn't poisoned by their exposure in the lab.  See: http://www.nzherald....jectid=10384337  

The powder form, on the other hand, is  much more readily inhaled as it is very light and highly electrostatic, so it floats around in the air as soon as you open the bottle.  I would be very careful to handle this in a chemical safety hood.

However, think about how many scientists have worked with acrylamide over the past 50ish years and think about how many have been affected by acrylamide!

[swanny]

bob1, on Aug 11 2009, 11:07 AM, said:

However, think about how many scientists have worked with acrylamide over the past 50ish years and think about how many have been affected by acrylamide!

... I wonder what subclinical exposure over a few decades would look like? Could it be differentiated from normal aging? And in any case, if one assumes the person in question made the standard promotions though the system, surely their exposure would decrease over time as they became more and more removed from benchwork, and more and more attached to an office chair, no?

having said that, bob's analysis (as usual) is pretty much spot on. Go for liquid acrylamide rather than powder: if you can't avoid the powder, use a fume hood.

As far as I understand, APS isn't especially bad, but deserves the standard respect given to all chemicals. TEMED, on the other hand does have some immediate consequences*, namely the release of a fair bit of ammonium. If you're worried about it, add the polymerising reagents in a hood.

Overall, just be alert when using the monomer and polymerising reagents and you'll be fine.


* I once knocked over a nearly-full bottle of the stuff, which caused the lab to be evacuated for an hour or so, plus I needed to use a Ventolin puffer for a couple of weeks.

[bob1]

swanny, on Aug 10 2009, 10:06 PM, said:

bob1, on Aug 11 2009, 11:07 AM, said:

However, think about how many scientists have worked with acrylamide over the past 50ish years and think about how many have been affected by acrylamide!

... I wonder what subclinical exposure over a few decades would look like? Could it be differentiated from normal aging? And in any case, if one assumes the person in question made the standard promotions though the system, surely their exposure would decrease over time as they became more and more removed from benchwork, and more and more attached to an office chair, no?

Yeah, I wonder about that too; for a lot of chemicals, not just acrylamide. I'm quite curious to see if we can distinguish the effects of long term plastics exposure, those things give off a lot of interesting bioactive molecules when heated.

[cellcounter]

Mummy, on Aug 10 2009, 12:02 PM, said:

Dear folks,

Being fairly new to the world of molecular biology, I would like to ask a tricky question from you: I want to learn more about the safety measures you use during acrylamide gel-pouring. Unfortunately our lab has no written rules, so I have seen wild things (people fingering the mixture with bare hands, etc.).
As far as I understand, One would have to work in lab coat, gloves (nitrile if possible - latex gets penetrated by acrylamide in a matter of minutes), and should not leave any acrylamide mess around (it will get absorbed through the skin if others touch it). I heard that the acrylic substances are pretty nasty, as the limit of no-adverse-effect (NOAEL) is below the 0.5 mg/day/kg level. And if neurotoxicity (risk of paralysis) would not be enough, its also a strong mutagen, causing cancer & translocation on chromosomes (risk of heritable genetic damage). And - if I could forget - ammonium persulfate (APS) and tetramethyl-methylene-diamine (TEMED) are kind of nasty, too! And...we tend to wash the equipments in regular tap water, reusing the pipette tips & tubes I guess that's not the best thing for the environment...

So I would welcome any advice I could use myself and spread to my colleagues as well!

If I remember it right, acrylamide has even been found in fried potato chips and baby milk bottles!

[lab rat]

Quote

If I remember it right, acrylamide has even been found in fried potato chips and baby milk bottles!

I've heard that too. I know firsthand that polyacrylamide can be found in some hair gels.

Sorry to get off track--I used to pour large-format sequencing gels horizontally, "coverslip" the gel with the top plate, and then clamp the top plate to the bottom plate. Our lab safety rules were:

Use the designated "pouring" bench only.
Cover the bench with liner, and discard after the gels were set.
When pouring gels, reserve 2-3 ml and pour into a test tube. When the mixture in the tube set, it was safe to handle the gels.

We always wore gloves (though not all of us wore lab coats ) when pouring gels. In retrospect, we should have worn goggles...the PI liked to use a syringe to fill in air bubbles, and would eject the air trapped into the syringe by holding the syringe needle-up and pushing the plunger until the acrylamide solution came out!

Edited by lab rat, 12 August 2009 - 11:56 AM.

[DavidJ]

Acrylamide is indeed a pollutant of not well prepared (starchy?) foods. The black bits of burned chips and the like contain it. However, whether this amount of exposure is dangerous remains controversial.

For gels we do what has been said. Liquid acrylamide with gloves (no coat). We only use TEMED in the hood, but that is beacuse it smells kinda really bad.