Making the great leap out of the 19th Century…”Acid-Fast” staining

The “standard” acid-fast differential staining process for the “High G+C Gram-Positive” bacteria[1] as we learned it is pretty archaic.

It goes something like this:

  • Smear and heat-fix the slide
  • flood the slide with Carbolfuschin
  • Heat the slide for 5 minutes in steam over a boiling water bath
  • Rinse with “Acid Alcohol
  • Stain for a minute with Methylene blue.

At the end, anything “Acid-Fast” (having a “waxy” outer layer) will show up red, anything else will be blue.

My objection is the messy and time-consuming steam-bath.

Today’s lab included one “unknown” which we suspected to be a Mycobacterium, so while one of us was going through the tedious 19th-century-style procedure, I decided to try something.

The steambath heat is just intended to (I believe) slightly “melt” the waxy layer of the cell and otherwise help “drive” the dye into it. So, instead of dealing with the time to make a water bath, heat until it steams, and then wait for the slide to sit there and hope the bubbling bath doesn’t splatter the slide with crud, I just stuck the flooded slide in the lab microwave and cooked it for 20 seconds.

It worked. Quite well, actually (other than letting the slide dry out, leaving some crystals on the slide) – the bright red mycobacterial cells showed up nicely. I’m annoyed that my ‘stick the camera up to the eyepiece’ technique came out slightly out of focus (I may see if I can enhance it later – if so, I’ll post it.). Somebody commented that it looked as good as a “textbook” example, which was nice for my ego…

Unfortunately, I guess I’m far from the first person to think of this. I don’t know if anyone’s done this exactly the same way, but This procedure describes directly heating the Carbolfuschin in the microwave and soaking the slides directly in it. There is also apparently an old Lancet[2] article which I don’t currently have access to – I’ll have to check it out later.

Next thing to do is try the endospore stain this way. Behold, the miracles of applying last century’s technologies to the problems of century-before-last!

[1] Ehrlich P. Zur Fa¨rbung der Tuberkelbakterien. Aus dem Verein fu¨r innere Medizin zu Berlin. Deutsche Med Wochenschr 1882; 8:269?270
[2] Hafiz, S., R. C. Spencer, M. Lee, H. Gooch, and B. I. Duerden. 1984 . Rapid Ziehl-Neelsen staining by use of microwave oven. Lancet ii:1046.

This is your brain. This is your brain on Microbiology…

In an effort to eat a relatively healthy diet, I occasionally eat pieces of wholesome, natural fruit.

There, I’ve admitted it. I can no longer live the lie that I only eat junk-food. Of course, to maintain some appearance of having a normal mainstream type of diet, I at least tend to go for the pre-cut fruit mixtures – I’ve got way too much going on to have time to prepare cut fruit salad from scratch.

Anyway, a few weeks ago I had a platter of these, still sealed in their plastic container, and didn’t get around to eating them in time. About a week after it had expired, when I went to throw it away, I saw a few little white lumps growing all over the pieces of fruit. Non-fuzzy, so I expected they were bacterial rather than fungal. Of course, there’s only one thing I could think when I saw that.

“Oh, wow! It looks like there were only about 5-8 bacterial CELLS on each piece of fruit when I got them! Those things were really CLEAN!”

(Of course, once you can SEE the colonies growing, there are a lot more than a few cells there. Each visible colony’s probably got millions of the little buggers, but each colony starts as a single cell.)

This was, of course, followed by me lamenting that I didn’t have some culture supplies and a microscope of my own to examine them with. Sigh. Anybody out there have any extra microbiology equipment you’d like to donate to a good cause?

So, what’s next? Should I try to start a series of bacterial taxonomy posts? Searches for “what’s a gram-positive?” and “what’s a gram-negative?” sorts of questions seem to be popular ways to reach this blog…

About this blog

(I’ve only got a couple more days before the start of “Just Science” week, so if I’m going to get this post up, I’d better get to it…)

Now that I’ve briefly explained who I am, here’s the bit about this blog itself.

My intended audience:
Anyone who’s interested. Okay, that’s kind of a cop-out. Essentially, I’m aiming at anyone who’s sufficiently scientifically-minded to be interested. I’m kind of assuming that if and when I’ve got enough readers to consider a “core audience”, it’ll be made up largely of interested science students, people who are inclined to read magazines like “Scientific American” or “Discover”, and just generally reasonably intelligent people with an interest in scientific matters, particularly but not only microbiology. I’m hoping that I’ll reach the point of being able to write so as to be interesting to some scientific professionals but still comprehensible to people without much of a scientific or technical background. This blog is, in part, an exercise in “public access to scientific information”, so if I write anything badly or fail to explain something, please comment and let me know.

How it works:
It’s easy: I think of something that I find interesting and that I think someone else might also find interesting, and I post something about it here. I expect to focus primarily on microbiology-related science, but a wide variety of topics might come up. I have a particular fondness for subjects that I think are underappreciated or ignored in other venues. Comments on whether or not things I bring up are interesting or boring will help guide the topics. I’ll tend to focus more on informal and hopefully pleasant to read style rather than a dry but detailed technical discussion – though wherever possible I’ll include links to that kind of information for anyone who’s interested (or perhaps thinks I’ve gotten it wrong.).
I also try to make the postings somewhat interactive – at the very least, I try to add extra information, explanations, and comments wherever I think they might be helpful or just entertaining. If you see words or phrases with thick dotted underlining, you should be able to “hover” your mouse cursor over it and get a little bit more information. I generally try to do the same with links and pictures. Maybe once in a while I’ll get bored and plant an Easter Egg or two.
Comments are welcome and encouraged, other than “spam”. What little information you’re required to give in order to comment is entirely to discourage spammers.

Really, this is mainly for personal gratification – I like to write. I like science. I’d like to share this interest, and I think scientific information would be interesting to many more people if more of it was presented in an interesting and accessible manner without making it seem otherworldly or dumbing it down to the point of uselessness. This blog is a cheap and easy way to get practice.
It’s also a cheap and easy way to get free learning for myself – I find trying to explain something helps me recognize when I don’t know something as well as I thought, helps me understand things better, and occasionally is a handy way to find out when something that I think I know is wrong.

Addendum: Yes, my Mom reads my blog. No, she does not wear combat boots. No, she does not dress me funny.

About this blog, Part 1: Me.

I thought it’d be useful to do a couple of posts explaining who I am (this post) and what I’m hoping to accomplish with this blog.

Don’t worry, I’ll try to be concise.

In a metaphorical nutshell: I’m a general-purpose nerd with a 15-year history of being a reasonably hardcore computer geek. I’m now escaping that field, and am a continuing undergraduate (at least as of right now.) who’s been painfully puttering part-time through college for many years off and on until recently – they don’t seem to make much provision for ““Non-traditional” students in US colleges. I’m now hoping to actually finish and graduate this summer – and then find an appropriate graduate program in whatever part of the country I end up in afterwards.

My area of academic interest is Environmental and Industrial (“Applied”) Microbiology. Medical microbiology, which seems to get all of the attention and funding, is somewhat interesting, but I’d rather people be able to benefit from anything I learn without having to get sick first.

In particular, at the moment I’m interested in exotic modes of respiration in prokaryotes. Or, more colloquially, fun (and preferably useful) ways of playing with live bacteria and electricity at the same time.

I’ve also got some interest in science history, public policy, writing and other forms of mass communication, public access to science, travel, food and food science, and at least casual interest in a wide variety of other areas. As such, you can generally expect that most of this blog will focus on microbiology and microbial biotechnology related topics, but will occasionally veer off in odd directions.

I also hope very much that someone besides me will get some pleasant usefulness out of this blog, so I strongly encourage comments, suggestions, corrections, and so forth.