The phages when infect bacteria present in the colonies, the results can be viewed within 15 hours. The effect of phage infection is visible to the naked eye as clear areas. Those clear areas are called as plaques. The plaques are clear areas in the opaque lawn of bacteria. The plaques are usually large or small, fuzzy or sharp, depending on their genome. In the figure 5-28, the recombinant plaque types are h+ r+ and h- r- with the physical features forming small, clear plaques and large, cloudy plaques.