"Lasers"

Do you like Star Wars? I do. I'm not one of those freaky, dress-up like Chewbacca fans, and talk like yoda, I do not, but what I really like about Star Wars are the lasers. It just seems like such a practical way to shoot things. No need to carry along a bunch of ammunition, all you need is your trusty multi-KiloWatt laser. Another benefit is that light travels, well, at the speed of light, much faster than a speeding bullet or a falling bomb. Lasers are used all over the place, most-notably for me, Flow Cytometry and Microscopy, but now it seems like the vision of Star Wars may be closer than ever. Darpa (The advanced research division of the Department of Defense) has been investigating weapons-grade lasers for some time, but with the use of some newer technologies, there may actually be a viable option. HELLADS, or High Energy Liquid Laser Area Defense System, a laser system developed by Textron, is getting some big government bucks to design and test a 150kW Laser Weapon System that could be carried on a Fighter Jet and be used to shoot down missiles. So, what's so special about the laser? It seems this laser system is using a series of thin ceramic slabs, bathed in rapidly circulating coolant to achieve a high power output while maintaining a non-destructive temperature load. These so-called slab lasers are attempting to tackle a long-standing problem with lasers, what to do with waste heat. If successfully employed, these types of technologies may trickle their way down to us lowly folks in the flow cytometry world, and I may actually be able to realize my goal of a centralized laser depot with a bunch of fiber-optic cables extending out of it. I've already got a name for it...Medussa! If you have a high enough laser source, you could split that beam a bunch of times, and using fiber optic cables, bring the light to any number of instruments using a "plug-n-play" connection scheme. Some day...

Flow Basics is Back! and slimmer than ever!

That's right folks, by popular demand, we're reintroducing a legend, Flow Basics. But, Wow Flow Basics, have you been working out? I mean, you're about half the size as the last time I saw you. You've gotta be down to, what, like 5MB or something? Not only is Flow Basics back, but it's leaner and meaner than ever, well, not really meaner, but definitely leaner. We've trimmed a bunch of the slides while still focussing on the most important aspects of basic flow cytometry theory and instrument usage. We will once again be making this a mandatory requirement for new flow cytometer trainees, but anyone who did not attend the original flow basics, will want to attend one of these training sessions. To make this process easier, we will be offering the course more frequently especially in the next coming months. Once the initial rush is over, we will over the course every other week as new users are being trained. We're also putting the course schedule on the facility's Online Instrument Scheduler, so now, you'll know exactly when the next class will be offered, as well as have an opportunity to sign up whenever is convenient for you. Although the Online Scheduler offers convenience and flexibility, the sign-up process has a few steps to it that may make it somewhat challenging the 1st time you attempt. So, we also made a little video demonstration on how to sign-up for training. We've embedded the video here for you to watch. Classes start 12/10/08, so check the online scheduler for more dates and to sign up.

561nm Laser Demo - MoFlo

We will be having a demo of a 200mW 561nm solid state laser on our MoFlo December 2nd and 3rd, 2008. Beckman Coulter will be in to install the laser as well as a detector block so we can assess the utility of such a laser for our sorting applications. The major benefit of this laser will be the ability to excite fluorochromes not normally excited at 488nm or 633nm, such as mCherry, RFP variants, and more. Other benefits of interest will be the stronger excitation of PE and PE-Tandems as well as the lack of spillover of blue excited fluorochromes like FITC and PerCPCy5.5 into PE channels. This will effectively increase the resolution of dimly stained populations, especially when identifying cells which are double positive for FITC and PE. We have a few scheduled demos of the laser with users of the facility, so if you'd like to see the laser in action, give us a call to find out what time we'll be running samples on the 2nd and 3rd. Or, just drop by on either day to take a look at the setup.

New - Flow Data Flickr Image Pool

New - Flow Data Flickr Image Pool
Originally uploaded by UCFlow

Why not stop over at the UCFlow Image Pool on Flickr (www.flickr.com) and check out some of the photos of data, instruments, and other things of interest. Or, better yet, why not send an image of your own to the flickr pool. All we ask is that it be flow cytometry related. If you want to send your image, simply compose an email to whose60which@photos.flickr.com. The Subject line of the email will be the photo's title, and the body of the email will be a description of the photo (make sure to remove your signature so it doesn't become part of the description). Then just attach the image, and send it along. It will be posted to the flickr pool, and randomly displayed on the facility's home page, http://ucflow.uchicago.edu

Where would we be without GFP?

In light of the yesterday's announcement of the 2008 Nobel Prize in Chemistry, I'd like to take a minute to demonstrate the importance of this work. The prize will be shared among Osamu Shimomura, Martin Chalfie, and Roger Tsien for the discovery and development of green fluorescent protein, GFP. Yep, that's right, good ole GFP finally getting the props it deserves. Truly, where would science and discovery be without GFP? I estimate that at least 50% of the cell sorting done in our facility is for GFP or its analogs (CFP, RFP, YFP, etc..), and I'm sure that scenario is repeated in every major Institution with a Flow Core. Even in simple flow cytometry analyses, GFP is many times one of the colors people typically look at. If you do a Pubmed search for keyword GFP, you'll get over 15,000 hits, and GFP hasn't even been around THAT long. I won't go into the history of GFP here, but if you're interested, just check out the wikipedia entry. If you're at all familiar with using GFP, then you undoubtedly have heard of or read papers by Roger Tsien, who not only did the early work on using GFP to label proteins in living cells, but has gone on to develop a whole slew of variants. These variants have different spectral properties and expression rates and stabilities, but they all pretty much work the same way. With the addition of many distinct fluorescent proteins, investigators now can label 3 or 4, or more proteins simulataneously in living cells. So, congratulations Shimomura, Chalfie, Tsien, and, of course, GFP.

eBiosciences New Fluorochrome Options = Repackaged Qdots

eBiosciences (www.ebioscience.com) launched a new set of fluorochrome options for their antibody line. They're calling these fluorochromes, eFluor(TM), and they'll be directly coupled to select antibodies immediately. If you're familiar with the Qdot technology currently offered by Invitrogen (www.invitrogen.com), then you're already familiar with eFluor; A nanocrystal core of Cadmium, Zinc, and Selenium with a biologically active coating to allow antibodies/proteins to stick to it. Even though this is simply a repackaging of an already established technology, it will be a great addition to flow cytometry and imaging cytometry. The ability to combine eBioscience's great line of antibodies with the Qdot technology will make using these things more of a reality. Invitrogen has had a pretty limited stock of directly conjugated antibodies, and hopefully eBioscience can expedite this process. The main advantage of these fluors is the ability to use multiple nanocrystals together using a single 405nm or 355nm laser without a ton of compensation. The emission spectra of these nanocrystals are so tight that it allows you to pack them close together without overlap. Also, by putting some of your antibodies in the UV or Violet channels, it frees up your visible laser channels for other, sometimes more important antibodies. To find out more about eFluor, as well as look at what's available so far, click on over to http://www.ebioscience.com/ebioscience/efluornanocrystals.asp for more information.

FlowJo Mac v.8.8 New Features

FINALLY!!! This has been on my list of FlowJo improvements for a long time. One of the features I like best on the DiVa 6 software is the ability to bend quadrant lines to account for the spread that is revealed after you compensate. The positive fraction is always a bit higher than the negative fraction. Therefore, it only makes sense that the line you draw to differentiate between single positives and double positives should have a positive slope to it. The slope of the line will depend on the amount of spillover and the spread that ensues. It was nice being able to easily match that slope with a set of quadrants in DiVa, but that wouldn't translate into FlowJo, so you were forced to create individual polygons for each of the populations. And, when you attempted to do this, it was nearly impossible to get all the gates to line up without any whitespace inbetween (more about that in a minute). But now, FlowJo has introduced in the Mac version 8.8 (go figure, the Windows version falls behind again) 'Spider Gates'. Just option-click the center point of the quads and move to bend the quad lines. Wonderful! My only complaint in actually using this is that after you convert your standard quad gates into a spider gate, you can no longer simply grab the center point and move all 4 quads at the same time. You need to do a select all gates function (cmd+a) and then grab the center. A small price to pay, I think, but hey guys, if you're listening, that'd be nice. The second new gating function is what they call molded gates. This gets back to the point of not being able to get all my polygons to match up exactly with no whitespace and no overlap. Now, if you select a bunch of gates (shift-click them, or cmd+a to select all of them) you can hit cmd+opt+m to 'Mold' the gates together. The couple of tries I've made thus far have worked really well. The gates must be 'nearby' meaning that you'll have to spend some time (albeit, much less) to get the gates close, but then, voila! it just works. If you have any questions/problems, send me an email, or submit your bugs directly to folks at FlowJo.