Does your lab have a closet full of white elephants; once expensive instruments that are no longer fit for purpose, or have broken down? In many cases, all of that wasted money and resource could have been saved if the buyers had made smart choices about matching the instrument more closely to their needs.

A real-time PCR instrument is one of those potential white elephants. Many factors go into the decision on which real-time PCR instrument to purchase. It’s a very expensive machine that will play a critical part of reaching your research goals so getting the right machine for your lab is essential.

This very topic was the subject of a recent discussion in the BioTechniques Molecular Biology Forum. Experienced users gave their input into what they considered most important in a real-time PCR instrument and I have collated the information to produce this essential buyers guide.

So here are the most important features to consider in a real-time PCR instrument

1. Fast run times. The most commonly stated requirement was fast run times. This allows more work to be done in a day. This is especially important if the instrument is shared or you have big projects and need high throughput.

2. Multiplexing capability. Many commented that the ability to multiplex is a plus point. You may not be doing it now, but its good to have the option in the future. Plus if it’s a shared instrument, the machine will need to have the flexibility to work in everyones project.

To this end, asking the manufacturer about the type of optics becomes important. Lasers are expensive, lamps are cheaper. Some lamps have broader excitation than others (eg xenon) than the more typical tungsten. LEDs are cheaper still and have a long life-span – but single LED instruments have lower numbers of channels

3. Flexibility of the plate format. You may have different projects / groups using the same unit. Some may have a 96 or 384 plate or even 0.2 ml tubes. A system that can use different plates will be a plus.

4. Ease of use. The user interface should be clear and intuitive.

5. Well-to-well variability. Some companies claim their machine is more accurate than rivals. When testing the instrument in house, try out some of your most difficult primer sets and make sure to use some of the outside and corner wells. A 0.5 degree well to well temp variation could have a major effect on PCR efficiency.

6. Customer support. What is the current expertise of the people involved in real-time PCR? If you have a lot of new people, they will be calling technical support frequently. How is the companys support? If it’s a shared instrument, will there be a designated expert to oversee the operation and help people internally?

6. Warranty. Most come with one year, some with two years. It is especially important for those systems have lasers to ask about the warranty options and figure that information into the cost.

7. Ongoing service contract. As with any major piece of instrumentation, you should consider taking up an ongoing service contract. This may be with the manufacturer or an independent company. Not taking up a service contract is a false economy – within a few years of heavy use your shiny new machine is likely to have died and gone to white elephant heaven.

So next time you are involved in buying a real-time PCR cycler, put these items on your tick-list. Ask the company reps about the features of their machines, then narrow it down – take a few demos machines and test them out rigorously.

Don’t be responsible for yet another white elephant!

This post is the result of a discussion in the BioTechniques Molecular Biology Forum.
Thanks to forum members WISBiomed, Nonrad, Mchlbrmn, WeirdOmen for their valuable input.

Photo: Kurki15