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Choosing a spectrophotometer cuvette for the first time can be a daunting experience. Following the simple guide below will allow researchers to quickly and easily select the correct cuvette for any experiment.
Spectrophotometer or fluorometer cuvette
The most basic question to answer when selecting a bucket is what type of machine it goes into. If you go into a spectrophotometer, then the two parallel windows should be polished. If an investigator is using a fluorometer, all four optical windows must be polished. It is important to note that a spectrophotometer cuvette will not work in a fluorometer, but a fluorometer cuvette will work in a spectrophotometer.
What material is better?
Depending on the type of experiment, the material from which the cuvette is made is very important. For researchers working in the UV range, they need a special UV quartz that can transmit from 190-340 nm. The most common range that scientists work in is the visible range, or VIS, which is 340 to 2,000 nm. For this range, there are three different materials available depending on the laboratories budget.
IR quartz is the most expensive material covering 190 to 3500 nm. Next comes quartz UV which covers 190-2500nm. And the cheapest option for a VIS experiment is optical glass that covers 340-2000 nm. If a researcher does not want to reuse a cuvette, he can find disposable spectrophotometer cuvettes that can be thrown away after one use.
Which light path to choose
Light paths are how many millimeters light has to travel before it leaves the spectrophotometer cuvette. Light paths can vary from very small, e.g. 0.01mm, up to 200mm. The biggest determining factor in selecting the proper light path is the sample size an investigator uses. If the investigator has a large sample, then a 10mm light path is the industry standard. If a scientist has a small sample that is very expensive, like DNA/RNA, then he should use a small light path cuvette to preserve his sample.
putting it all together
The above three factors, spectrophotometer cuvette or fluorometer cuvette, material, and light path are the three fundamentals needed to choose a cuvette.
Once a researcher has answered these three questions, they are ready to choose the simpler features, such as what type of cover is best for the experiment.
Following these three simple guidelines makes choosing a spectrophotometer cuvette a breeze, even for recent graduate students.