Viable and total cell masses in dental plaque as measured by bioluminescence methods.

Bioluminescence methods have been applied to the measurement of the viable and total cell masses of small samples of dental plaque. The total adenine nucleotide content of dental plaque samples and of a pure culture of bacteria was determined and the adenylate energy charge calculated from this. When a pure culture of bacteria was killed with heat, the adenylate energy charge decreased exponentially with duration of treatment and corresponded with a decrease in the count of viable organisms.