Miniaturized two-fold dilution method for enumerating total microbial load and coliforms in raw milk

M. Costello, Min-Suk Rhee, D. H. Kang

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A rapid and simple method for enumerating total aerobic plate counts (APC) and coliforms in raw milk was developed and compared with conventional plating method. Following two-fold serial dilution of samples in a 96 well rnicrotiter plate, double strength of two different modified media for APC or coliforms was added to each well. The final positive well (purple to yellow color) was determined and converted to dilution factors. The dilution factor of each sample was converted to Log 10 DF (Dilution factors) and compared to actual microbial numbers Log 10 CFU/mL. The results of 2-fold dilution method (Log 10 DF) were strongly correlated to conventional plating method (Log 10 CFU/mL) (P < 0.05). The correlation of the scatterplot of spread plating and 2-fold dilution method indicated a high level of agreement between two methods (R 2 = 0.921 for total counts and R 2 = 0.916 for forms from raw milk). This 2-fold dilution method is an easy, rapid, and economical method for enumeration of total microbial loads and coliforms in raw milk.

Original languageEnglish
Pages (from-to)19-25
Number of pages7
JournalJournal of Rapid Methods and Automation in Microbiology
Volume10
Issue number1
Publication statusPublished - 2002 Aug 17
Externally publishedYes

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microbial load
raw milk
Milk
methodology
plate count
Color
sampling
color

ASJC Scopus subject areas

  • Food Science
  • Microbiology

Cite this

Miniaturized two-fold dilution method for enumerating total microbial load and coliforms in raw milk. / Costello, M.; Rhee, Min-Suk; Kang, D. H.

In: Journal of Rapid Methods and Automation in Microbiology, Vol. 10, No. 1, 17.08.2002, p. 19-25.

Research output: Contribution to journalArticle

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