Figure. Results of polymerase chain reaction testing of clinical specimens (for which dates of collection were available) from a patient with inhalational anthrax (patient 2), are illustrated by date of collection relative to the initiation of antimicrobial drug therapy. Bacillus anthracis was not recovered from any of these specimens on which culture was attempted (data not shown). A. Blood, n=45; B. Pleural fluid, n=8.