Things Are Not What They Appear

So I finally received my Arsenic in the mail the other day. Actually, it's not Arsenic, per se, but a salt compound called sodium arsenate. When the salt is dissolved in water, you then have a mixture containing sodium ions and arsenate ions. Arsenate, commonly referred to as As[V] due to its pentavalent electron structure, is often encountered in nature. And detection and monitoring of arsenate is a research effort of notable interest due to its high toxicity - it is Arsenic after all.

We've set about developing a detection method for arsenate, which is based on one overarching principle of the substance: As[V] quenches fluorescence. This is theoretically true, as the arsenate ion should act as a potent electron acceptor. There are several research groups using fluorescent silole compounds to detect the presence of As[V] via electron quenching in such a manner. See here (subscription required) and here.

But there's a problem with all this. I tried to replicate Stern-Volmer quenching plots for As[V] last week and...well...let's just say I didn't get the same results. My results were not necessarily bad; just unexpected. I'm sure that the data will end up in a manuscript shortly. And once the paper is published - which will be in, like, two years - I'll post a link to it on this blog. Until then, you'll just have to imagine what the data looked like...

Making Enemies is Job #1

I started working at Lincoln University in December of last year. Since that time, a colleague and I have been sharing a lab with a faculty member and space has been tight. We were promised a larger lab right next to our office, but it has been previously used as sort of a community lab space by several researchers. And let's just say habits are hard to break. News went out a couple of weeks ago from university administration that the lab had been handed over wholly to my faculty supervisor. Last week my colleague and I watched with delight as equipment and supplies were cleared from the lab. Over the last couple of days, we have been finishing clearing equipment that won't be used and moving supplies into storage that we won't need.

Unfortunately (but not for me) some of the other researchers came by the lab looking for supplies that had already been tossed out. Oops. Sorry about your bad luck, but the lab was supposed to be cleared weeks ago, actually months ago. And pretty much everyone else in the building got mad because we stacked all of the unwanted equipment in the hallway so that LU Surplus Property could haul it away; they considered it an eyesore. So the equipment was scattered throughout other parts of the building where they would not be so obtrusive. My guess is that they will remain in those out-of-the-way corners for a few more decades. Or until the end of time. Whichever comes first.

The way I look at it: my purpose at LU is to help build the cooperative research program into an advanced, innovation-producing machine. It's difficult to do that with fifty-year-old instruments. My purpose at LU is not to make friends, and so I'm not going to worry too much about making a few enemies.

MUG: It's Not Just For Coffee Anymore

Recently, I have been playing around with a special cell culture media that uses a fluorescent indicator to signal the presence of E. coli bacteria. The culture media is a nutrient broth called LST-MUG, and is often referred to by its proprietary name, Hach media. The nutrient broth is similar to other types of cell culture media, with a couple of notable exceptions. First, the media contains surfactants that inhibit the growth of non-coliform organisms. This basically means that everything but E. coli is killed in the broth, allowing only E. coli to grow in the media. Second, the media contains a molecule called 4-methylumbelliferyl-β-D-glucuronide, or MUG. MUG is the part of the media that is responsible for indicating the presence of E. coli.

Under normal conditions, MUG emits very weak fluorescence at a wavelength down around where blue and UV meet, somewhere around 400 nm, when exposed to UV light. When MUG is introduced to E. coli, it is cleaved (or cut) into two separate smaller molecules by an enzyme within the bacteria called β-glucuronidase. One of the products of this cleavage reaction (the glucoronide part) is basically inert and does nothing at all. But the other product of the reaction is 4-methylumbelliferone, a highly fluorescent molecule. When exposed to the same UV light as before, the fluorescence of 4-methylumbelliferone is easily observable as a pale blue glow. In this way, the MUG acts a fluorogenic reporter of the presence of E. coli bacteria.

This bacterial growth media with the fluorescent reporter is commercially available and widely used to detect the presence of E. coli. However, it has some pitfalls. One problem with the media is that the sample to be tested must be introduced to the broth and then incubated, which is best done in a laboratory environment by a trained technician. A more pressing issue with the broth is its response time, which is 16-24 hours. If you are testing a sample of, say, raw beef, you would take a random in-line sample during processing and inoculate the Hach media. Twenty four hours later, a fluorescent signal is observed in the media, indicating that the beef is contaminated with E. coli. But that particular beef product is already on a truck on its way to the grocery store.

One of the projects that we're focusing on at LU's Center for Nanotechnology & Biosensors is a method for making this process much more effective and drastically faster, so that E. coli can be detected efficiently and contaminated products can be kept off of store shelves.

Will The Cat Kill Curiosity?

The cat may not kill curiosity, but the federal government just might. A continuous underestimate of the costs required to design, build, and deploy the newest Mars rover has made its future a bit uncertain. You can read more about the ongoing problems with the Mars Science Laboratory here.

I certainly hope that NASA is able to get their house in order with this project.

And speaking of Curiosity, I'll take this as a chance to remind you that NASA's Jet Propulsion Laboratory has a live webcam in the cleanroom where the Mars rover is being assembled. It's pretty cool watching the rover come together, so I recommend following the link if you're interested in that sort of thing.

Spread Thin

As you may already know, a colleague and I recently started a start-up technology R&D company. My colleague and I are the operational managers (he is the President, I am the Vice president), and we own the company in equal shares with a third non-operational partner at Lincoln University who is acting as a scientific advisor. The company is called Emergent Sensor Technologies, and you can learn more about us here. We are currently in the process of requesting Small Business Innovation Research funding through a number of agencies. Our small arsenal of concepts are currently being developed for potential commercialization. The patents are pending on these, so until we have sufficient intellectual property protection for our concepts, I am going to avoid divulging any details on the projects. As these concepts mature, though, I plan to provide updates on their progress here on this blog, as well as the research section of our website, which is currently pretty much void of any useful information.

As you may also already know, I am currently a post-doctorate researcher at Lincoln University in Jefferson City, MO. Here at LU I work on and oversee various projects, write grant proposals (seemingly endlessly), mentor students interested in research, and manage several laboratories on campus. My lab work is split between overseeing projects being conducted by others as well as pursuing my own research interests. I really enjoy my work at LU, as I have a lot of latitude with respect to my research activities and am free to work on and request funding for my own little pet projects.

As you probably don't already know, I am in the process of taking on a third (and hopefully final) job as a senior research scientist at Mizzou, my beloved alma mater. As I finished my doctorate research at MU, I was conducting a pilot study in order to gather some preliminary data for a research project that was to continue after I graduated. The preliminary data was used in a small piece of a relatively large-scale research proposal, which was subsequently funded. So I have been called back to MU to oversee that portion of the project so that the deliverables that were proposed can be met in the short time frame of 1 year; the current duration of the project.

Yes, that's right. I will now be splitting my time between Emergent Sensor Technologies, Lincoln University, and the University of Missouri. Three different positions at three different institutions doing all sorts of different science-y things.

Can I handle it? Hell yes! I love science.

Cool Toys

Let me know when this becomes commercially available.

I want one.

Bikes Are So Freakin' Cool!

I love bicycles. I enjoy riding them. I enjoy working on them. In particular, I like rehabbing and restoring old bicycles. There's something about bringing a machine back to life that may have otherwise ended up in the landfill that fills me with pride. Plus there's a certain level of cool that vintage bicycles, especially 60s and 70s road bikes and roadsters, possess that is rarely seen in modern bikes. Something about the clean lines and simplicity of the thing I guess.

The machine that we now recognize as the bicycle has been around for a little over a century. And the physics of how the bike works and how it stays upright are fairly well understood. First of all, the bicycle has a particular geometry with respect to the position of steering that helps to keep it upright. Enhancing this effect are the rotation of the relatively large wheels of the bicycle. This rotational motion provides an inertial force or gyroscopic effect, much like the tail rotor of a helicopter, and allows the bicycle to stay upright even when it is not actually going anywhere. These phenomena are well studied and are fairly easy to understand.

But not so fast. A research group has eliminated the gyroscopic effects of the bicycle's wheels by adding a counter-rotating wheel and altered the traditional geometry of the bicycle by playing around with its form and shape. And what they get is a bicycle-like vehicle that is able to stay upright on its own, as long as it moves greater than a particular speed. Pretty mind-blowing stuff. You can see a video of it in action here, and also read more about the study and the conclusions. The research group believes that the ability of their machine to stay upright can be attributed to the fact that, like a traditional bicycle, the machine has a tendency to steer into its fall, keeping it from completely falling over when it begins to tip. But this is just a hypothesis. So the study has added a bit of mystery and intrigue to what was considered the ordinary, plain-old bicycle.