Price_1975_Clin.Biochem_8_384

1. A manual procedure, using propionylthiocholine, for the determination of serum cholinesterase and its genetic variants has been assessed in respect of its precision and of its ability to classify the genetic variants of the enzyme. 2. It is shown that the propionylthiocholinesterase activity alone is a useful guide in identifying individuals who are likely to be sensitive to succinylcholine. 3. In phenotyping with dibucaine and fluoride, sera of phenotypes U and UF could not be distinguished from each other with confidence, but were distinguishable from sera of phenotype UA.