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ERIC Number: EJ920473
Record Type: Journal
Publication Date: 2010-Nov
Pages: 3
Abstractor: As Provided
ISSN: ISSN-0021-9584
Dilution Confusion: Conventions for Defining a Dilution
Fishel, Laurence A.
Journal of Chemical Education, v87 n11 p1183-1185 Nov 2010
Two conventions for preparing dilutions are used in clinical laboratories. The first convention defines an "a:b" dilution as "a" volumes of solution A plus "b" volumes of solution B. The second convention defines an "a:b" dilution as "a" volumes of solution A diluted into a final volume of "b". Use of the incorrect dilution convention could affect the sensitivity and results of an assay. This could have serious consequences for a patient's diagnosis. Ideally, all solution concentrations should be expressed as molarity, molality, or normality, but this is frequently undesirable in commercial clinical assay instructions for proprietary reasons. To avoid confusion, it is critical that a statement be included at the beginning of the experimental portion of each protocol explicitly describing how dilutions are to be performed. The American Chemical Society and educators could establish and teach an unambiguous standardized dilution convention. This would ultimately eliminate the problem.
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A