Question

Hello, I need help with this question plz,

* Compare and contrast morphological and biochemical testing. Provide examples of activities/tests performed in our micro lab. Can microbes be identified using either of these methods alone? Why or why not?

Answer 1

MORPHOLOGICAL TESTING Is the most basic technique used for classifying bacterias based on cell arrangement and shape.So the basis of this technique is the use of a microscope and different stains in order to produce color contrast that allows the observation and characterization of the bacterias in study.

Type of stains :

simple : all bacterias stain with the same colour

negative staining: coloured background

Differential stains: Gramm or acid fast stain.Allows the differentiation and detection of particular bacterial strains based in some specific structural characteristics

BIOCHEMICAL TESTING are based in the use of preformed enzymes in bacterial cells.This methods shorten the time required to identify and ensure or enhance the accuracy of identification.In fact, this test give 70%-80% confirmation of type of bacteria

The routine tests include the following: carbohydrate fermentation, methyl red utilization, gelatin liquefaction, nitrate reduction, citric acid utilization, hydrogen sulfide production, catalase, oxidase and urease test

So, both types of testing are necessary for a correct and precise bacteria identification