Somerset Independent Schools

The technique they are practicing in the video is called the Gram Stain and is used to determine if the bacteria will hold a blue or red dye on their cell walls. This is a basic differentiation test used in clinical settings. To prepare the microbiology slides, the students first grew bacteria on agar plates and then heat fixed them onto glass slides. After the bacteria were fixed to the slides the students used special blue and red stains to determine if they were considered Gram positive (blue) or Gram negative (red). The coloration will be visible through a microscope. In a general sense, bacteria which stain Gram negative tend to be more prominent in bacterial infections. This activity is under the direction of SHS Biology Teacher Ms. Penley.