Date: June 8, 1998 Author: Michael BrushPoint of Use Water Filtration Systems He was described as a "grey-beard loon," but the superstitious old sailor of Samuel Taylor Coleridge's The Rime of the Ancient Mariner clearly understood the value of a reliable and consistent source of pure water. Trapped on a ship becalmed in the doldrums and faced with an exhausted fresh water supply, the old sailor lamented, "Water, water, everywhere, nor any drop to drink." The pure water requirements of the mode

BugStopper from Whatman, Inc. Out with the old and in with the new. Progress. Change. These ideas come to mind when one first encounters the BugStopper™, a new product from Whatman, Inc. Offered as a high tech replacement for the ubiquitous cotton plugs used for sealing culture flasks, the BugStopper revolutionizes the late 19th century's cotton plug with 21st century materials and technology. Resembling a large, hollow rubber stopper, the BugStopper is manufactured from transparent, me

he search for methods to visualize proteins resolved by electrophoresis on everything from cellulose acetate strips to polyacrylamide gels goes back to the origins of the electrophoresis itself. When DISC electrophoresis was introduced in the early 1960's (B.J. Davis, Annals of the New York Academy of Science, 121:404, 1964), amido black was the protein stain used most frequently. As the need for staining methods with increased sensitivity and staining uniformity grew to meet the demands of pro

"Aarrrggghhhh!" My cry of frustration echoed down the hall. My latest attempt to subclone five important PCR products had failed yet again. After two months of fruitless effort, I was at my wit's end until a colleague suggested I try the TOPO TA Cloning® Kit from Invitrogen. "Look," he said, "all you need to do is to combine 1 microliter of your PCR reaction and 1 microliter of the pCR2.1-TOPO® vector, add 3 microliters of water, and wait 5 minutes. Then transform your competent cells

Date: March 2, 1998 Chart 1 efrigeration is wonderful, especially when applied to centrifuges. Not only does refrigeration help maintain the stability of biological compounds whirling along at several thousand revolutions per minute, it also enables the use of higher speeds and g-forces. The friction encountered by a rotor spinning through the air in its chamber is enough to raise its temperature several degrees. Refrigeration counteracts this effect and thus expands the usefulness of centrifug

Date: January 19, 1998 Chart 1 Chart 2 Chart 3 They sometimes go by different names. Be it an "air-cooled," "ambient," "ventilated," or "nonrefrigerated" model, they are all the same thing: a microcentrifuge that gets cold only in the cold room. Useful and popular, there are plenty of nonrefrigerated microcentrifuges to choose from across a spectrum of styles, features,, and prices. LabConsumer contacted 19 manufacturers and dealers of nearly 50 nonrefrigerated microcentrifuges in compiling dat

Date: November 10, 1997 Chart 1 In the long series of events inherent in automated DNA sequencing, cranking out DNA labeled with fluorescent tags is, of course, the most important element of a successful procedure. Without properly labeled sequence ladders to analyze, those expensive, automated DNA sequencers have little to do. So to keep them busy, LabConsumer checked out fluorescent automated DNA sequencing kits from eight manufacturers. The kits profiled exploit two methods for labeling se

Date: October 13, 1997 Test Results Chart 2 Anyone who has manually filled and rinsed all 96 wells of a microplate knows what a chore that is and can surely appreciate the labor-saving benefits of an automated microtiter plate strip washer. Curious about the attributes of the latest crop of strip washers, LabConsumer invited four manufacturers to submit their instruments for a hands-on review. All the strip washers arrived with an 8 channel manifold for washing one 8 well strip at time, alth

Date: September 29, 1997 Table Comparing Products Imagine working in a life science lab without a centrifuge. Be it a microfuge, a general purpose centrifuge, or even an ultracentrifuge, little work would be accomplished in its absence. Unquestionably, these ubiquitous and indispensable instruments have made an incalculable contribution to our scientific understanding of the world. Where would we be without them? Fortunately, the centrifuge has come a long way since the old hand-cranked cont

When the next time around is always better. Date: July 21, 1997 Comparison Chart DNA sequencing methods have come a long way in 20 years. From the chemical method of Maxam and Gilbert and the dideoxy method of Sanger, DNA sequencing techniques evolved into the "labeling/termination" method that used a modified T7 DNA polymerase such as Sequenase. Propelled by the power and potential of DNA amplification using thermal cycling strategies, earlier DNA sequencing methodologies have increasingly b