In addition to trueness and precision, the term “accuracy” is often used in discussions about automated liquid handlers. A high amount of precision is equivalent to a small percent coefficient of variation. Identical measurements of the same volume. It is the closeness of a set of values obtained from Precision is defined as Reproducibility (% CV). A result of high trueness is equivalent to a small percent error. It is a percent error between the average volume of solution measured and the expected or accepted value. Trueness is defined as Yield (% trueness / bias).
It is a good practice to consider the pipetting specifications to be the best case scenario and to consider your own method’s pipetting performance requirements when evaluating verification results. These specifications can be used as a reference during verification, but keep in mind that differences in laboratory conditions, pipetting approaches, and liquid types can result in different performance. Each automated liquid handler has expected performance at various liquid volumes and tip sizes. The purpose of measuring liquid transfers is to check for a “true” and “precise” result. Keep in mind that measurement described on this page only provides you with a measure of the volume transferred. Liquids can be measured through a wide range of tests, from simple visual checks to more complex measurements that involve dyes or special scales. As part of our Automated Liquid Handling Guide, this page describes methods to measure transferred liquid volumes to ensure success.
Once the liquid handling is complete, it’s valuable to be able to double check the automated liquid handler and make sure that the liquid was transferred at the correct volume. Knowledge Base (Articles, FAQs, Downloads).