Thermal cyclers are quickly becoming one of the most important tools in the classroom laboratory, but why? Well, the versatility of the Polymerase Chain Reaction, or PCR, plus its ease of use makes it a perfect upper level activity for your biotechnology students. But, there is an associated cost. Thermal cyclers – especially research grade thermal cyclers – can be prohibitively expensive for the teaching classroom. Luckily, for most basic experiments, there are cost-effective thermal cyclers designed for the teaching classroom without sacrificing speed, ease of use, or reproducibility. When choosing a thermal cycler for your classroom laboratory, there are a lot of features to consider.
- Interface: In order for the thermal cycler to properly amplify your DNA, you need to input the cycling parameters – temperature, time, and number of cycles. Some use push button interfaces with small screens, others require programing using a stand-alone tablet, and still others have touchscreen interfaces.
- Speed: PCR works by rapidly heating and cooling samples to different temperatures to separate DNA strands, bind primers, and build new DNA from the building block nucleotides. Most thermal cyclers try to move from temperature to temperature as quickly as possible. This helps to prevent off target effects: primer dimers, non-specific primer binding, secondary structure effects in the template. All of these off target effects can affect the success of your PCR experiment. Most PCR systems use thermoelectric cells for both rapid heating and cooling. This is a neat STEM phenomenon in itself, as the temperature of the thermoelectric cells is controlled by changes in the voltage.
- Sample capacity: Some thermal cyclers have capacity for eight samples, others can handle over 300 samples! Sample capacity can make a huge difference in thinking about your classroom workflow. Classes are getting bigger, so having a larger capacity sample block helps with efficiency. For example, an eight sample PCR machine with 24 student samples means performing the amplification three times, or having your students work in groups and not getting the full PCR experience.
- Price: We all know classroom budgets are tight! “Entry-level” research thermal cyclers can start at $3000. But, just because your thermal cycler is inexpensive doesn’t mean that it should be cheap. Designing student ready thermal cyclers with research ready features, like a touch screen interface, active heating and cooling, and large sample capacity isn’t easy, but we know it can be done!
There are other aspects of the unit that are important for usability, but not necessary. This includes full color touchscreen interface, stand alone programming, a compact footprint, and even stylish design! But, for us, the most important feature of our thermal cyclers is the research quality results at a student-friendly price point! Recently, our friends at a local biotechnology company tested the EdvoCycler 2 and the EdvoCycler Jr against their more expensive, research grade ProFlex Base Thermal Cycler and found that they produced equivalent results! Like we always say, just because something was designed to be student friendly, doesn’t mean that it won’t stand up against more expensive, research grade equipment!