The use of acridine orange as a rapid method for the quantitation of bacteremia in laboratory animals.

A rapid technique has been developed to quantitate the degree of bacteremia in laboratory animals. Direct staining of blood smears with acridine orange and enumeration using fluorescent microscopy allowed quantitation of Haemophilus influenzae in blood at densities from 10(5) to 10(8) cfu/ml. This technique will facilitate the accuracy with which therapeutic trials are conducted in laboratory models of infection.