In recent years, the molecular biology aboom' has generated much development and diversity in gel documentation technology. Dr Paul N Goulding reports.
Gel documentation systems are used extensively in many laboratories for image acquisition from electrophoresis gels, either as print-outs or as computer files for archiving or analysis. The basic design is a camera for acapturing' the image, a transilluminator for illumination of the gel, plus some means of printing or archiving the image.
Today, systems in use range from instant camera systems producing a photographic print, to sophisticated charged coupled device (CCD) camera systems producing digitised images which can be printed or archived on computer.
It is sometimes assumed by prospective purchasers, that they should choose the system most sophisticated and highest specification model, within the available budget. This is not necessarily the case, particularly in the many laboratories where such systems are used with high frequency, for routine, repetitive work. In such laboratories and in environments where systems are shared between large numbers of users, there is a high level of dependency on the system as a valuable research tool. In these situations it is clear that reliability takes on added (and often, overriding) importance.
Reliability of any multi-component scientific equipment (or system) is dependent on a number of factors. However, broadly speaking the simplicity (or, lack of complexity) of a system should enhance reliability, since complex systems generally include more delicate and fragile components.
Such components are often more liable to long-term failure and also, may require a certain level of training for correct use and care, which is not practical in large, dynamic user groups. In the more sophisticated, modern gel documentation systems, components such as cooled CCD cameras, motorised zoom lenses and general automation (often computer controlled) are all available at a price.
While these features may be beneficial to the small number of users who have specific requirements for them, for others the aprice' may be reduction of long-term reliability in addition to financial considerations. What is more, the trend of abuilding-in' components (for example, cameras and automatic lenses) to the more sophisticated systems means that if these components fail, they require more time and expertise in replacement or repair. In simpler systems, a amodular' design can make component replacement simple and rapid. It should also be noted that asimple' systems discussed above are not normally deficient in the basic documentation and archiving functions required by most laboratories.
From the above arguments it can be concluded that, it is important for prospective purchasers of gel documentation systems to consider factors other than the system specification and level of sophistication. Features such as high camera resolution and extreme camera sensitivity are beneficial and may be essential in certain circumstances.
However, the potential hidden costs of such systems should be considered. Simplicity, and hence reliability and robustness should be considered as tangible, beneficial features to ensure that the most suitable system is chosen for the application in mind and not simply the most expensive.
ENQUIRY No 16
Dr Paul N Goulding is with UVItec Ltd, Cambridge, UK.www.uvitec.demon.co.uk
