Growth of <i>gua</i> and <i>pur</i> mutants in EMF12 supplemented with individual purines.

<p><i>H. pylori</i> strains were grown in EMF12 supplemented with one of seven purine sources. After 20 hours, the optical density was measured. Positive growth was defined as a statistically significant increase in OD₆₀₀ relative to the baseline OD₆₀₀ of 0.025 (student's t-test, P<0.05). Results are the mean ± SD of three independent growth cultures.