I found this semi-hilarious because, well, I do immunohistochemistry as part of my job, and I also do protein purification/analysis. For protein purification, we actually use two different detergents (Lauroylsarcosine, 1%, and Triton X-100, 2%) in order to get as much protein solubilized as is possible.
But the funny thing is that protein analysis uses a detergent that, in the lab at least, we call SDS. SDS stands for sodium dodecyl sulfate, which is also known as sodium lauryl sulfate. And if you check the back of your bar of soap, you’ll find sodium lauryl sulfate as one of the first two or three ingredients almost without fail.
In the lab, we put protein samples in 1% or so SDS and then boil them for five minutes to denature the protein.
I don’t recommend doing that when taking a shower.
LL
PS. (I’m still a newbie here, so feel free to yell if this should have gone in MPSIMS.)
Howdy neighbour! Great post. Any message expounding on a column written by the great Cecil Adams is welcome in this forum. Come back as often as you like!
You don’t want to go to MPSIMS anyway, the group down there is a bunch of rabble-rousers. The intellectuals hang out over here.
Cecil’s saying you don’t need to give the soap time to kill the germs? Then how come when doctors are scrubbing up for an operation, they have rules that say they have to stand there and scrub for 30 seconds or whatever it is?
Or am I misinterpreting the column? Hard to tell, what with all them big non-MPSIMS words flyin’ around.
Sodium lauryl sulfate is what’s in shampoo. You’re telling me it’s just detergent? Shoot.
Duck Duck Goose, I imagine it’s because the doctors are scrubbing that the exercise is useful, and if they just stood around with the soap on their arms without the friction, there would be no advantage.
Arnold’s partially correct. The scrubbing helps kill the germs, but in addition, scrubbing removed dead skin cells, hair, etc… the sort of stuff that turns into dust in your house. You wouldn’t want that inside you after surgery.
Yep, it’s in shampoo too, and it’s just detergent. Though “just detergent” is perhaps a little misleading. There are a large number of detergents out there, from mild to very harsh. The chemical definition of a detergent is, basically, a chemical that allows protein and oil to be soluble in water. It does this by having one hydrophilic end–usually a charged part that’s highly water-soluble–and one hydrophobic end, a part that looks like a fat. (For the record, the first detergents were made by mixing animal fat and lye, which produces, among other things, sodium laurate. Not as powerful as SDS, but still strong).
OK, now I’ve gone and used even more big words. Sorry, DDG
I grew up in the “Better Living Through Science” era, so I was obscurely pleased to be told that shampoo had exotic chemicals in it that “cleaned just like detergent, but better, and gentler.” So it’s not, huh? Oh, well, another cherished childhood belief bites the dust. What was it that somebody said, about “soap by any other name would clean just as well”?
Also, not wanting to get bogged down in too many 50-cent technicalities here, but I thought that what you got when you mixed animal fat with lye was soap, not detergent. Eh?
And I thought I learned in 6th grade science class that soap and detergent were two different things. You use soap on your face, you use detergent on your clothes. Is it just a question of harshness, then?
