The DRIFTCON software

Right after start up of DRIFTCON a pop-up window shows the machines to be measured. The cyclers whose turn it is to be validated are displayed in red. After selection of an instrument the user proceeds to the main screen, where one can choose from different options, or start a DRIFTCON measurement sequence.

The properties of the thermal cyclers that need to be checked regularly in your lab, can be added or edited, and the measurement frequency (daily, weekly etc.) can be defined from this menu.

The results of every measurement are stored and can be easily reviewed. Relevant basic information concerning the thermal cycler, DRIFTCON, user, protocol and external parameters can be displayed, as well as a detailed overview of all the measured parameters: accuracy, spread, ramp rates, maximum overshoot, average overshoot and hold time. The last parameter (hold time) shows the amount of time that a block is at a defined temperature plateau.

The two most important parameters, temperature spread and accuracy are presented at six different times or time intervals (10-20s, 15s, 25-35s, 30s, 85-95s, 90s). At every level the measured values are compared to the threshold values, and by means of a sign, judged right or wrong (within or out off thresholds).

The non-uniformity and accuracy can also be presented in a time-graph. With this graph one can visually follow the development of performance of an instrument in time, between set limits (thresholds). By moving the cursor on the graph, exact values are displayed.

There are two options when it comes to thresholds: (1) choosing to compare to the field specifications (the average worldwide performance of a certain brand and type of cycler), or better, (2) empirically determine the borders of a certain test (e.g a HIV detection), and set the found values as predetermined thresholds. This is done in the “settings” menu, even per temperature plateau (30, 50, 60, 70, 90 and 95°C).

Instruments thresholds (the average market performance for one specific instrument and block type) are provided with the purchase of a DRIFTCON system. Other brand/block-type specific threshold settings may be purchased as software “add-on” (optional). These specific instrument thresholds are extracted from the global CYCLERtest database, which contains numerous measurements of machines of that same brand and type. These values are provided as a mean plus or minus 2x the standard deviation (so they equal 95% of the population).

Although the design of the application thresholds are much more difficult and time-consuming, application thresholds are superior to instrument thresholds. In other words: application thresholds offer a real view whether or not the used cycler is suitable for this application. In case of a commercial (diagnostic) kit (PCR, LCR, Real-Time PCR, RT-PCR etc) one may request the temperature profile thresholds from the kit manufacturer. Should the kit manufacturer not have these thresholds available, then it is worth considering visiting or participating in our discussion forums at this website.

Three user levels can be defined: Administrator, Controller, and User. The Administrator has full access to all possibilities of the software. This person can create other users and change their settings, set threshold values and alter other controls. The Controller is not able to do this, but can add and edit instruments. A User is just able to perform measurements and view results only.

To be able to judge the DRIFTCON results versus a frame of reference, it is possible to exchange measurement data with the CYCLERtest database. In exchange of these values access is granted to the most up-to-date field specifications of the brand and type of instrument used.