Fatty Acid Analysis

Fatty acid (FAME) analysis and Phospholipid Fatty Acid (PLFA) analysis by gas chromatography have been used commercially since the mid-1980s. The technology is very rapid, accurate and inexpensive per test. Additionally, for bacterial identification, FAME analysis is an effective tool for strain tracking, an advantage over other microbial identification techniques (e.g. MALDI-TOF, 16S rRNA and Biochemical-based systems).

Microbial ID offers fatty acid analysis using the MIDI Sherlock® Microbial Identification System - the only automated fatty acid analysis system available. With over 750 literature references from around the world to its credit, the Sherlock® System uses gas chromatography and sophisticated pattern recognition software to identify over 1,500 species of bacteria and yeast based on the unique fatty acid methyl ester (FAME) profiles of each strain.

Microbial ID provides strain tracking, with the Sherlock® Dendrogram and Sherlock® 2-D Plot Analysis programs.


The Dendrogram program uses cluster analysis techniques to produce unweighted pair matchings based on fatty acid compositions. The results are displayed graphically in a diagram that depicts the relatedness of pairs of entries. Multiple analyses and experience with the program have shown that species link at about 10 Euclidian Distance, subspecies at about 6 Euclidian Distance, and strain at about 2 Euclidian Distance. Duplicate Bacillus strains, due to the great variability encountered from spore production, link at about 3 Euclidian Distance.


Lower linkage indicates greater similarity. In the example above, none of the samples link below 3 Euclidian Distance; therefore the unknown does not belong to any of the known strains.

As a sister company of MIDI, Inc., we have more experience with fatty acid analysis technology and the Sherlock® system than any other lab worldwide.