Gram Staining

Recognize the presence of bacteria through incubation and staining

Some strains of bacteria can be nearly indistinguishable from other strains. Various strains of bacteria may even share indistinguishable growth rates or affinity for the same agar. In order to differentiate, gram staining can be a fast and effective process. Stains of bacteria in question can be inoculated on multiple petri plates or even in separate quadrants of the same plate. The plates are incubated in an incubator, like the Incufridge at an optimal temperature, like 37C or lower. When the growth is determined sufficient, the petri plate is washed with various dyes. The reason this is done is because different bacteria may have a chemical affinity for different stains. If the bacteria absorbs the stain, the bacterial colonies that have an affinity for the state will change color, while the other bacteria that does not have an affinity for the stain remains visibly unchanged. For a closer analysis, the IncuCount, automated colony counter can be used to analyze and count the stained and unstained colonies. Aseptic techniques should be employed. Petri plates should be properly disposed of after they are no longer needed, by sterilizing in an autoclave, like the Saniclave 50.