Streak Plate

This is a blood agar plate on which Staphylococcus epidermidis has been streaked. The pattern of growth indicates the manner in which the bacteria had been applied to the plate, noting in particular the way a small amount of bacteria was dragged from one area to another area on the plate. This manner of application is called streaking for isolation should result in the separation of a mix of bacteria into individual colonies. Ideally, each individual colony started from a single bacteria which, if grown on a nutrient plate of its own, may then be considered a start toward obtaining a pure culture. However, this is not necessarily always the case, especially if the bacteria can stick to one another, therefore the colony represents the bacteria that were in the starting "clump" of bacteria and not the progeny of a single bacteria.

Close window to return.