One of the most common applications of a UV/Visible spectrophotometer is to measure the concentration of nucleic acids. Often there is very little sample available and the researcher may not wish to dilute it further in order give sufficient volume for measurement in a standard quartz cuvette. There are ultra-micro quartz cuvettes available which will allow as little as 20μl of sample to be measured directly, however they can be quite difficult to use to achieve reproducible results. An alternative, if the sample is of a sufficient concentration, is to use a TrayCell.