Run samples in replicate. To help evaluate the extent of error, each standard and sample should be tested in replicate (duplicate or triplicate, depending on the number of samples and room on the plate). Afterward, the average, standard deviation (SD), and coefficient of variation (CV) can be calculated to provide confidence in pipetting precision. As a best practice, the replicates should have a CV of less than 20%. If the CV is higher than 20%, consider the following (Reasons the CV may be high):