Incorrect use of ratios in commercial assay kit instructions

摘要

Many tests in clinical laboratories use fully automated 'closed systems' but others use manual techniques or generic 'open systems' such as enzyme immunoassay (EIA) plate processors. These latter techniques rely on accurate manufacturers' instruction sheets. Errors in these have implications on patients and unambiguous instructions are important.Kit instructions often use the terms 1:x and 1/x interchangeably in describing dilution steps despite these having distinct meanings. Instruction to dilute a sample 1:10 indicates addition of one part of sample to 10 parts of diluent, whereas 1/10 indicates addition of one part to nine parts of diluent. Discussion with a small number of scientists in our laboratory demonstrated that some considered the terms interchangeable.