Determinación de la correlación entre métodos visuales ópticos y difusión en placa en el crecimiento de Escherischia coli

Abstract

The correlation between optical methods: Spectrophotometer and turbidimeter, visual method: McFarland scale and the reference method of plate diffusion were evaluated in order to determinate the concentration of Escherichia coli at 9 hours. The visual method doesn´t have a correlation with the reference method because is a qualitative method and the measurements are subjective. In the case of the optical methods, the spectrophotometer had an error of 91,4 percent in comparison of the turbidimeter with an error of 2,2 percent. The turbidimeter was the only method which has a correlation with the reference method and can be used as an alternative for the traditional plate diffusion method.