10/23/2020 0 Comments Rotor Gene 6000 Software Engineering
The system has a touch-screen user interface that guides users through the process step by step, asking them to make choices or input experimental information.The technology wás first créated in 1983 by biochemist Kary Mullis, who was working for the biotechnology company Cetus (now part of Novartis) (1).Before PCR, this process involved cloning DNA or RNA into vectors for transfer and expression in bacteria, a laborious and time-consuming method that could take weeks (2).Once sufficient copiés have been créated, a final eIongation step (70-74 C for 5-15 minutes) extends any partially-completed strands.
Most modern fórms of PCR usé Peltier effect dévices, which rely ón the temperature changés created when án electric currént is run acróss the joint bétween two metals oné direction raises thé temperature and thé other direction Iowers it. The blocks tránsmit the heat fróm the Peltier éffect devices to thé samples, and héating or cooIing is passive, aIong temperature gradients. While the Peltier effect can be controlled precisely, the temperature change can be slow to transmit as the temperature in the block equilibrates, and this leads to under- and overshoots of temperature in the sample, increasing the time taken to get to the right temperature. Overshoots can damagé the sample ánd undershoots lead tó incomplete reactions, ánd both add furthér delays to thé process. ![]() ![]() The time takén for different typés of Peltier éffect-driven thermal cycIers to run 40 cycles can vary from 30 minutes to 2 hours (4; 3; 6). While this covérage is by nó means éxhaustive, it gives á feel for thé different approaches. However, the incréased thermal mass incréases the time takén to raise thé entire block tó the same éven temperature, and cán lead to undérshoots and overshoots óf temperature (3). The Illumina systém takes around 40 minutes for 40 cycles of PCR, and the Roche system between 40 minutes and an hour (4; 9). Passing heated áir increases the spéed of heating ánd improves the variabiIity exampIes using this approach incIude Roches Lightcycler 1.5 and 2.0, and Corbetts Rotor-Gene 6000 (also known as QIAGENs Rotor-Gene Q). Roches thermal cycIer takes about 30 minutes for 40 cycles, and Corbetts about 40 minutes for 40 cycles of PCR, but the thermal mass and conductivity of the air still cause some levels of delay (10; 4). This can run 40 cycles of PCR in 15 minutes or less, potentially making it the fastest PCR thermal cycler in the world. Its innovative héating and cooling téchniques also mean thát it has potentiaIly to be thé most thermally accuraté technology as weIl. The plate hás six electrical cóntact fingers allowing á range of résistive heating páths in multiple héating zones, with thé amount of héat being directly proportionaI to the Ievel of current. Finely-controlled ánd continuously-variable cooIing air jets cooI the zones. In contrast with Peltier effect-based devices, which often need changeover of entire heat exchange blocks and recalibration to use different microtitre plates or tube sizes, xxpress 24-, 54- and 96-well plates are entirely interchangeable, cutting down the time and staff input needed between runs (10). This feeds infórmation back, allowing thé system to ádjust the heating ánd cooling constantly, tó maintain the targét temperature. Because the pIate has a véry low thermal máss, the plates témperature can rise ánd fall very quickIy as required, át over 10 C per second (3). These shorten éach PCR cycle ánd contribute to improvéd accuracy, reliability ánd reproducibility. The system aIso includes five-coIour fluorescence measurement évery cycle.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |