Hot Stuff: Annual Thermocycler Roundup

Courtesy of Biometra Biometra's TGradient Things are getting hot in the thermal cycler world. Since The Scientist's last annual review of thermal cyclers,1 a number of vendors have updated their product lines, and several plan to release new products within the next year. With improved user-friendliness and visual appeal, the thermocycler class of 2003 features something for every user. Most thermal cyclers use thermal engines based on the Peltier effect, in which heat is transferred from one side of a semiconductor to another, eliminating the need for refrigerants and compressors. Other systems use circulating air or water baths, or a combination of Peltier, resistive, or convective technologies. With so many options, PCR novices may have trouble making a decision. Product managers cite a number of items to consider when purchasing a thermal cycler. First, some instruments feature gradient functionality or the option to upgrade to real-time PCR. A number of cyclers offer interchangeable blocks or modules that can be added to the system as needed. Another factor to consider: whether the instrument is GLP-compliant and/or licensed for PCR. Finally, the vendor's customer service reputation is key to preventing a PCR standstill should the equipment malfunction. SO MANY CYCLERS, SO LITTLE TIME UK-based ABgene offers the H2OBIT™ (pronounced "Hobbit") high-throughput thermal cycler (manufactured by KBiosystems), a water-based instrument that can accommodate up to 108 microtiter plates simultaneously, giving it the highest capacity of any thermal cycler, says product manager Simon Ng. The system employs a robotic arm that transfers plate baskets between three water baths, giving it ramp times similar to those of circulating air-based instruments. Reactions also can be run at very low volumes (1 µl), reducing the amount of reagent required and lowering costs when compared to conventional Peltier-based systems. Foster City, Calif.-based Applied Biosystems' GeneAmp® line of conventional thermal cyclers includes the personal-sized 2700 model as well as the 9700 series, which feature interchangeable blocks. The company also offers options for real-time PCR users, including the ABI PRISM® 7000 Sequence Detection System, which has a 96-well block and is designed for low-throughput applications. The ABI PRISM 7900HT Sequence Detection System is the only real-time instrument to offer interchangeable blocks, according to Chris Grimley, product line senior manager for DNA platform business. The 7900HT can accommodate a 96-well, 384-well, or microfluidic card block and is available with an automation accessory. Courtesy of Thermo Electron Thermo Electron's PXE Cycler Hercules, Calif.-based Bio-Rad's newest entry in the thermo- cycler market is the MyCycler™, a Peltier-driven, personal-sized instrument with a 96-well block and optional gradient capability. Bio-Rad's iCycler™ thermal cycler features interchangeable blocks and the ability to upgrade to the MyiQ™ or the iCycler iQ™ for single- or multicolor real-time PCR respectively, simply by adding an optical module to the 96-well iCycler. Product manager Hilary Srere explains that unlike some competing instruments, the iCycler iQ system can be used as a stand-alone thermal cycler for conventional PCR even when another person in the lab is using the system's computer for data analysis. Both the MyCycler and the iCycler come with large high-resolution displays and easy-to-use interfaces. Each Peltier-based thermocycler from Biometra of Göttingen, Germany, includes gold-plated silver as a block material, rather than the standard aluminum, to provide higher thermal conductivity and better temperature homogeneity across the block. Biometra's cyclers feature smart-lid technology and unique spreadsheet-style programming. These include the compact TPersonal; the "workhorse" T1 Thermocycler with multiple, exchangeable blocks; the PC-controllable T1 Plus Thermocycler; the TGradient, which features a temperature gradient of up to 40°C; the T3 Thermo-cycler, which offers three independent cyclers in one housing; and the robotics-compatible TRobot. The life sciences division of Chelmsford, Mass.-based Brooks Automation offers a high-throughput, air-based thermal cycler as part of its Parallab™ 350 Biological Nanoliter Workstation. Rather than using standard microtiter plates, the Parallab system uses a nanopipetter with 96 glass sample capillaries. The capillaries aspirate each reagent from conventional microtiter plates that are then placed in the thermal cycler to "form a forest of glass reaction vessels in an air-based racetrack," says life sciences product manager Sean Rubin. The system has very fast ramping speeds (up to 10°C/sec) in part because the reaction tubes and volumes are much smaller than those required by traditional thermal cyclers; the volume needed for each reaction is 1/42 of that in a typical protocol. Courtesy of Bio-Rad Laboratories Bio-Rad's MYCycler Cepheid of Sunnyvale, Calif., now offers an updated version of its SmartCycler® microfluidics-based system. The SmartCycler II uses the same ICORE® temperature-controlled modules, which allow each sample to be subjected to different protocols. In contrast to the original version, the new model features an improved spectral separation to facilitate multiplexing. Cepheid offers a portable version of the system, the SmartCycler II TD, which includes 16 independently programmable sites. A newcomer to the market, Continental Laboratory Products (CLP) of San Diego, manufactures the Apollo line of instruments, Peltier-based cyclers that feature a small footprint, bright blue lids, and user-friendly programming. CLP's economical ATC 201 features a combination block and touch-screen programming, rather than the standard keypad. The ATC 401 offers 20°C gradient thermal cycling and an "IQ-Therm" lid that automatically adjusts to provide the right amount of pressure for the user's specific plates or tubes. Future releases will include robot-compatible, modular, and real-time cyclers. Sydney, Australia-based Corbett Research's Cooled Gradient Palm-Cycler™ features a unique control panel: Users program the system via an integrated PDA for gradient, touchdown, long-range, and PCR protocols. The system offers a 24°C linear gradient function and automatic temperature calibration. Corbett's Rotor-Gene 3000™ is a four-channel, multiplexing, real-time PCR system with a centrifugal design. Rotors designed for either 0.1 ml or 0.2 ml tubes (with a disposable rotor as an option), spin in an air chamber to ensure temperature uniformity across samples. The TLC Rotor™ (for automated temperature calibration) and Optical Denaturation™ are two recent additions to this instrument system. This fall, Eppendorf of Hamburg, Germany, will release a new line of Peltier-based cyclers. The Mastercycler® ep system incorporates a number of new features, including improved programming and ESP™ lid technology, which eliminates preheating of the sample prior to cycling, thus preventing formation of nonspecific primer hybrids. The Mastercycler ep system separates the control panel from the thermal module; up to five different modules running independent programs can be controlled by a single keypad, offering a high degree of flexibility and minimizing the costs associated with increased throughput. "We wanted to have a system that could grow very comfortably together with the lab's needs," says Cordula Kroll, marketing manager for molecular and biotechnology. The system also features impulse PCR, which Kroll describes as machine-driven hotstart PCR, to optimize specificity. Eppendorf will continue to offer its original Mastercycler line as well. Within the next year, Salt Lake City-based Idaho Technology will release the RapidCycler® 2, a spinoff of its original RapidCycler thermal cycler, which combines circulating air heating and cooling with capillary tubes for high-speed thermal cycling (30 cycles can be completed in less than 10 minutes). The RapidCycler 2 is designed specifically for Roche capillary tubes. Another new product to be launched next year is a battery-powered, field-portable, real-time thermal cycler that cycles by moving liquid in plastic pouches from one heating zone to another. The system involves no pipetting, and reagents are integrated within the platform, making it lightweight and easy to use for field applications. For military uses, the RAPID (Ruggedized Advanced Pathogen Identification Device) integrates Idaho Tech's original LightCycler (now licensed to Roche Diagnostics) into a portable, airtight, and watertight system, says technical services specialist Matt Scullion. MJ Research (MJR), headquartered in Waltham, Mass., was the first company to manufacture Peltier-based cyclers and continues to manufacture its own Peltier elements in-house; these elements are optimized to minimize thermal stress, increasing reliability, says Mike Mortillaro, vice president of sales and marketing. Basic products include the personal-sized PTC-100 and MiniCycler. MJR's DNA Engine™ thermal cyclers all feature gradient capability; the line includes the single-bay DNA Engine cycler, the four-bay, high-throughput Tetrad® cycler, and the Dyad® thermal cycler, which allows up to four different protocols to be run simultaneously with two Alpha sample-block modules. A new addition, the Dyad Disciple™, doubles the capacity of the Dyad without expanding the footprint. The DNA Engine cyclers can be upgraded to real-time PCR via the addition of an optical detector that fits on top of and around the cycler, or users can purchase an integrated real-time PCR system, the DNA Engine Opticon 1 or Opticon 2. Spokane, Wash.-based MatriCal will be launching its MatriCycler high-throughput thermal cycler at the end of 2003, says company cofounder Kevin Oldenburg. The MatriCycler is Peltier-driven but does not rely on thermal blocks, which take a long time to heat and cool. Instead, pin-shaped Peltier elements on the cycler's lid insert directly into the wells of a specially designed microtiter plate, heating each sample well independently and speeding the heating rate up to 20°C per second. Courtesy of Thermo Electron ARMED AND READY: Thermo Electron's MultiBlock thermal cycler with robotic arm Ebersberg, Germany-based MWG-Biotech offers the Primus series of Peltier-based thermal cyclers. The standard Primus cycler can accommodate multiple-block formats and comes with a self-adjusting heated lid. Primus HPL instruments feature MWG's patented high-pressure lid technology to prevent sample evaporation. MWG also offers a Primus model for in situ applications, as well as dual- and multiblock systems for high-throughput and robot-integrated applications. The company plans to update its thermal cycler portfolio in the coming months. Indianapolis-based Roche Applied Science licensed the circulating air/capillary tube thermal cycling technology developed by Idaho Technologies for its LightCycler™ real-time PCR system. The newest version of the system, the LightCycler 2.0, offers six-channel fluorescent detection and can be used with either 20-µl or 100-µl cuvettes. The BioOven III Thermocycler from St. Johns Associates of Beltsville, Md., uses circulating air technology and can handle samples in a wide variety of formats; it also features a rotating carousel to ensure temperature uniformity. Company director Peter St. John notes that many users are now interested in running multiple assays and that the BioOven III's high capacity makes it ideal for this purpose. Stratagene of La Jolla, Calif., offers two real-time PCR instruments, the Mx3000P™ Real-Time PCR system and the Mx4000® Multiplex Quantitative PCR system. The Mx3000P system is a high-performance, full-featured system with a small footprint and a low cost, says product manager Tiffany Scarborough. The Mx4000 system offers a flexible, universal platform and uses a hybrid system of Peltier, resistive, and convective technologies for tight temperature control. Both systems support all quantitative PCR chemistries and are designed for multiplexing up to four different fluorophores in a single tube. Stratagene also offers the RoboCycler line of thermal cyclers, which include four thermally programmable blocks and a robotic arm that moves samples from block to block. This procedure reduces experiment time because the samples are automatically moved to the appropriate temperature block for each point in the reaction, eliminating the need for temperature ramping. Burlington, NJ-based Techne plans to update its existing line of thermal cyclers within the next year; the new products will feature longer warranties and enhanced software. Currently, the company's offerings include the personal-sized Techgene; the Touchgene Gradient thermal cycler, which has a range of 30° C and features an easy-to-use touch-sensitive screen; and the high-throughput Flexigene. A Flexiquad system (Flexigene-based) also can be purchased in a reduced-price four-unit/block configuration with PC control. All of Techne's thermal cyclers are Peltier-based. Thermo Electron's molecular biology division, located in Milford, Mass., continues to offer a wide range of thermal cyclers, including the more basic PxE and PCR Sprint cyclers, and the Px2 thermal cycler, which features interchangeable blocks and a gradient option. Thermo Electron's MBS system consists of individual "satellite" blocks linked to a central computer. Users can add one block at a time as their needs grow, says marketing manager Sara Howland. A robotics-compatible version of the MBS system, MBSR, features stackable blocks to save laboratory space. Aileen Constans can be contacted at aconstans@the-scientist.com. 1. A. Constans, "Some like it hot," The Scientist, 15[24]:32, Dec. 10, 2001. INSTRUMENT VALIDATION Courtesy of Cepheid The rise of real-time PCR has led growing numbers of users to seek independent means of validating their cyclers' performance. UK-based Quanta Biotech offers a thermal cycler validation service for this purpose. Mark Ebdon, director, explains that in the past, users who wanted to validate the performance of their thermocyclers had to send the instrument back to the company that manufactured it. The problem with this is that different vendors use different types of validation tests, not all of which are traceable to international standards; Quanta's service is NIST traceable to ITS 90. Quanta offers four test levels ranging from bronze to platinum; the tests differ in the number of wells interrogated and the level of protocol reproduction. Quanta also manufactures the TAS line of validation systems for end users (available under the Apollo label from CLP). TAS systems are used on a daily basis by end users to troubleshoot PCR applications, validate equipment, and transfer protocols between cyclers from different vendors. A number of factors can influence brand-to-brand variations in instrument performance, including the age and design of the cycler. Ebdon notes that the number of Peltier engines used in each instrument can vary, thus leading to variations in thermal profiles across each block. Further, most thermal cycler manufacturers do not have a common standard by which they specify instrument performance, and specification measurements can be taken at different times after reaching target temperature. Finally, in the race to speed up protocol time, users often reduce the time at target temperature. "That puts them into a kind of no-man's land, because there's no real published specifications from any of the thermal cycler manufacturers on the variance across the tubes when they're in temperature transition, and in the very few seconds after you've reached a target temperature," Ebdon explains. function sendData() { document.frm.pathName.value = location.pathname; result = false if (document.frm.score[0].checked) result = true; if (document.frm.score[1].checked) result = true; if (document.frm.score[2].checked) result = true; if (document.frm.score[3].checked) result = true; if (document.frm.score[4].checked) result = true; if (!result) alert("Please select") return result; } .myradio{background-color : #94bee5} Please indicate on a 1 - 5 scale how strongly you would recommend this article to your colleagues? Not recommended 1 2 3 4 5 Highly recommended Please register your vote

Hot Stuff: Annual Thermocycler Roundup

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Courtesy of Biometra
Biometra's TGradient