The ABI GeneAmp™ system 2700 is a simple, inexpensive, thermal cycler with a small footprint. The small foot-print means that this device makes good use of available bench space, allowing this device to fit into any laboratory – it will even fit easily on the researcher’s personal work bench. The desktop footprint measures only 36 x 21 cm (14.2 x 8.3”) and it stands 22 cm (8.7”) above the desk. Because the air-flow for the cooling system is located at the back of the unit, several machines can be stored and operated side-by-side, with no space between, for efficient space usage.
The machine has one 96-well, Peltier-cooled, aluminium block that can accommodate single tubes, tube strips, or trays. All of these consumables are readily available from ABI and many other third-party suppliers. As with most current-model thermal cyclers, the machine has a heated lid to avoid sample evaporation. Unlike many other thermal cyclers, the heating element in the lid of this model is not protected from access. When open, the heating element faces directly towards the user and therefore may present a possible burn risk (the lid is heated to 103oC), although if the user is aware then the risk is minimal.
The GeneAmp™ 2700 maintains temperature accuracy to within 0.25oC and can vary the temperature at a rate of 1oC per second. Programs executed on this machine are very reproducible due to the highly uniform heating and cooling. The machine runs diagnostics and self-tests every time it is switched on (or when requested by the user). It can test the uniformity of heating, heating and cooling rates (to avoid inaccuracies in the set temperature end-points), any many aspects of its operation to ensure the accuracy of the programs. In fact, although this machine can be purchased for almost half the price, it has the same reliability and performance as many of the larger and more expensive systems available from ABI. This makes units are very cost effective in comparison to many other PCR machines.
As with the majority of ABI instruments, using this machine is simple. Menu and program control is facilitated by simple ‘arrow’ movement controls, a set of ‘function’ keys and a numeric keypad. The ‘function’ and ‘arrow’ keys are used to navigate through a well designed menu system which is displayed on a large and bright LCD. Programming the unit is trivial and, although a very comprehensive manual is provided, it is not needed because of the intuitive interface. The machine has a memory capacity for 100 cycle sequence programs which can be sorted, saved and deleted. There is no facility for connection to a PC, or memory card slots for expanding the capacity of the machine (other than firmware upgrade purposes). The programs and run results can be sent to a printer when connected.
The cycling program is displayed as a simple representative graph showing the temperature and time at each point during the cycle. The program is entered by typing in a temperature at each time point on the graph and as the cycle proceeds, the graph is displayed to indicate the point through which the program is currently running. The machine is capable variable temperature ramp speeds and can perform most common program types including set-temperature holds (i.e. non-cycling programs), touch-down, time-release, pre-heating and so forth.
Unfortunately, the heating and cooling is slower than some PCR machines available at only 1oC per second. This means that the cycles will take longer than many other instruments – although, of course, this is not intended to be a high-throughput machine. The cycler is not capable of running temperature gradients across the block as is the case with many other machines.
Overall, I would recommend this unit for general PCR requirements. It is a very reliable and easy to use machine that will perform the majority of basic PCR requirements quickly, quietly and easily.
Scott Coutts
Department of Microbiology
Monash University
Australia