Gradient choice points in PCR analysis, although there are a variety of PCR primer design software or the empirical formula the optimum annealing temperature for a PCR reaction, but because of the ever-changing combination of the template in bases for a particular piece, empirical formula obtained The data is not necessarily able to "P" out results, subtle changes may have a decisive impact on results, thus "touch conditions once very stressful. Gradient PCR emergence of a partial solution to some problems - the temperature control conditions of each hole in the course of the reaction can be within the specified range in accordance with the gradient according to the result, a step can be worked out the most suitable reaction conditions. Not only the annealing temperature, and even the denaturation temperature and extension temperature can be optimized - amplified by a variety of polymerase enzyme mixture, such as manufactured by Invitrogen, Clontech, Promega majority fidelity Taq enzyme, this is very important, because the Taq and proofreading enzyme The reaction temperature may have a significant difference, optimization extension temperature, it becomes very important. Many experiments can be completed on a single instrument, saving both the experimental time and improve efficiency, but also saves the cost of experiments. With functionally gradient PCR instrument, you need to consider the uniformity and accuracy of temperature gradient mode gradient tube row, you must also consider whether it has the same temperature characteristics of the instrument in the gradient mode and standard mode. This difference may cause results to differ alone do under optimal conditions derived in gradient mode and standard mode. SteadySlope technology eppendorf owned gradient PCR technology patents, can reach all set to the same rate of temperature change temperature gradient having a constant temperature, so in the gradient mode. This technique ensures the reliable transmission of information, and not because of the different temperature characteristics resulting yield and specificity of the change in the gradient mode and the normal mode can be performed. The MJ company does not pay royalties to the different cooling rates and select the gradient mode, different temperature curve between each gradient temperature conversion problems may arise from the gradient mode to normal mode. Besides using TCT (Triple Circuit) technology gradient PCR to ensure the accuracy of the gradient of temperature control and better uniformity of the different gradient of temperature between the tube rows in the control region of one of heating and cooling due to an increase in the gradient PCR mode, . Increase in the PCR instrument in situ PCR module can be on a slide in situ PCR amplification, MJ and of eppendorf the PCR instrument, are provided in situ adapters to meet different needs. Buy with PCR instrument to support in situ PCR module of workers engaged in medical research is worthwhile, in one machine. In addition, with the improvement of the demand for high-throughput genome, the various brands have launched a multi-slot high-throughput PCR instrument, each with its own specialty: MJ a One to four, with four amplified trough is a host, Each slot can control temperature independently, once for 96x4 sample PCR, but if there are problems 4 can be used not. ABI is introduced on the basis of the original 9700 double base of 384 holes, once 384x2 samples, making the 9700 feature is extended to the field of high-throughput without having to buy a new machine, but unfortunately two 384 slot can not be controlled independently temperature. eppendorf have a control panel, you can control the five separate PCR instrument, each machine can be combined, and independently of each other, but more wasted space. Functional and user-friendly design of the instrument is of course the more simple and convenient design that best meet the requirements of the user. Thermal cover - gradient PCRhttp :/ / www.jntckj.cn/ instrument generally are equipped with thermal cover hot lid temperature is set to 105 ° C, the temperature at the top of the sample tube to about 105 ℃, evaporation of the reaction solution will not generate agglutination reaction volume change in the pipe cover, so that users do not need to be added to the reaction tube add paraffin oil, directly reduce the trouble of the subsequent reaction. If it is rotating pressurized hot lid must be very cautious, because no obvious pressure reaches prompt, users need thermal cover spin to the right location based on experience, not very easy to grasp. If too loose, the thermal cover is not full contact with the reaction tube to affect the results; too tight, it will lead to a reaction tube deformation, and may even cause the thermal cover mechanical failure. Latest ESP technology is a thermal cover decreased thermal cover heating when not in contact with the sample tube, to avoid heating of the sample tube led to a non-specific product, and other heated to a set temperature and pressure, the sample tube into the heating module, down time and pressure by the electronic Control. Sample base - PCR reaction in more than 0.2 or 0.5 of the tube, the most PCR instrument with different replacement samples Slot sample tube. eppendorf an interesting design, a tank with 0.2 and 0.5 are two different sample hole, no need to replace the base you can use two different reaction tubes or 96-well plates, plus situ adapter can becomes situ PCR. To avoid the trouble of changing the base. Of course, different reaction tubes can not be used simultaneously because of different height, thermal cover will not. ABI 9700 can switch to a different sample tank, the sample tank series was amplified from the 0.5 to the standard 96-well, to the dual 384-well plates, respectively, for different needs, and quite flexible. Software - new PCR instrument are paying more attention to the ease of programming. Large-screen, real-time information, countdown, memory storage, multiple programs, automatic power-off protection and so contribute to the complex environment to use in the laboratory. Program stockpiles, some people think that the number of the stored procedure seems to sense is not very large, but for laboratory personnel, PCR instrument daily operation of frequent laboratory, each user is independent store custom PCR program, really convenient under time of the call, will save some time. Considering a PCR Instrument optional key lies with the user's own requirements, some features may have no access to or rarely use, users need to be scrutinized, after all, is what you pay for.