Lab Report : Biological Testing Essay

1611 Words Nov 11th, 2015 null Page

In this lab report I use two different techniques to identify Unknown A and Unknown B bacteria’s. These techniques are gram staining and metabolic testing. I first used Gram staining to distinguished and identify the bacteria’s. Han Christian discovered gram staining in 1882, he had biopsy a patient lung that had pneumonia. The main purpose for Gram staining is to identify if is Gram positive or Gram negative by using differential staining. While Gram staining shows the difference between Gram Positive and Gram negative and its size, shape and morphology. This techniques as it limits. For example, I was doing Gram staining and I noticed that I had more then one gram- negative with rod shapes and gram -positive with coccus shapes. This make it very difficult to tell which ones were my unknown A and unknown B so, I needed to do further testing. This testing is called metabolic testing. Since bacteria’s have different genetic makeup and produce different types of enzyme that are unique in the way they help with biochemical reaction. Metabolic testing is testing how a particular bacteria grow or breakdown certain agar/ medium that contain certain nutrition that will have a biochemical reaction if it is positive or negative.

Method one


There were two different unknown bacteria. Which are “Unknown A” and “Unknown B”. In which I will do bacteria smear on two separate slides. Before I started I first have light the Bunsen burner and inoculate my…

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