Code of Federal Regulations Title 42. Public Health § 42.493.1261 Standard:  Bacteriology

(1) Each day of use for beta-lactamase methods other than Cefinase^TM.

(2) Each week of use for Gram stains.

(3) When each batch (prepared in-house), lot number (commercially prepared), and shipment of antisera is prepared or opened, and once every 6 months thereafter.

(1) Each day tests are performed, the laboratory must use the appropriate control organism(s) to check the procedure.

(2) The laboratory's zone sizes or minimum inhibitory concentration for control organisms must be within established limits before reporting patient results.