69. The Burri Smear-Culture Method for the Determination of the Bacterial Content of Milk Samples

Abstract

1. A comparison has been made of the accuracy of the ordinary plate and Burri smear-culture methods for the determination of the bacterial content of milk samples.2. In determinations made by the smear-culture technique the percentage error has been shown to be markedly higher than in those made by plating.3. Evidence is presented in support of the view that the inaccuracy of the Burri method (as ordinarily employed) when compared with the plate technique is partly due to the errors involved in loop measurements and partly to the inferiority of the conditions for growth on slopes to those in plate cultures.

Thermoduric Organisms in Milk. Part V. A Simplified Testing Technique

“…With this in mind consideration has been given to the use of a lo-* ml standard loop or similar device for inoculating laboratory pasteurized milk into 2% melted agar medium in tubes according to the agar strip method of Stirling et al (1950). Cunningham & Andrews (1934) and many other workers have shown that loops are less accurate than pipettes, but for a creamery grading test for advisory purposes only, some loss of accuracy would not necessarily be a serious objection. Berridge (1954) compared the standard mi cylinder as a measuring device.…”