Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:In an attempt to standardize the bacteriologic procedures, all patients had a ‚Äúendocarditis diagnostic kit,‚Äù using an automate (Bactec Becton Dickinson, Sparus, Maryland) including standard BC and special samples for isolation of intracellular pathogens, and for various specific antibodies (7).
Category: