The Petri dish—a shallow glass or plastic dish consisting of two round, overlapping halves (also called a cell culture dish)—is used to grow bacteria and other microorganisms on a certain medium, usually in the nutrient agar. The top of the dish is larger than the bottom so that when the dish is closed, a seal is created, preventing contamination of the culture; some are also loose-fitting, with either used depending on the experiment. This device was developed in 1887 by German bacteriologist Julius Richard Petri (1852–1921), a member of Robert Koch’s laboratory (for more about Koch, see above). Petri dishes are very easy to use, can be stacked on each other to save space, and are one of the most common items in a microbiology laboratory.

Bergey’s Manual of Determinative Bacteriology is an extensive reference manual used for bacterial classification. The first edition was published in 1923 under the sponsorship of the Society of American Bacteriologists (organized in 1899 and now known as the American Society for Microbiology [SAB]). This reference work was first conceived by bacteriologist David H. Bergey (1860–1937) with the assistance of a special committee of the SAB. By 1994, the ninth edition of the book had been published.

Bergey’s book also spawned two other works under the name Bergey’s Manual of Systematic Bacteriology. Whereas the 1994 book is used as a reference to aid in the identification of unknown bacteria, the newer manuals offer systematic information about bacteria. The first edition of Bergey’s Manual of Systematic Bacteriology includes four volumes: Volume 1 (1984), Gram-Negative Bacteria of General, Medical, or Industrial Importance; Volume 2 (1986), Gram-Positive Bacteria Other Than Actinomycetes; Volume 3 (1989), Archaeobacteria, Cyanobacteria, and Remaining Gram-Negative Bacteria; and Volume 4 (1989), Actinomycetes. The most recent, second edition was published in five volumes beginning in 2001: Volume 1 (2001), The Archaea and the Deeply Branching and Phototropic Bacteria; Volume 2 (2005), The Proteobacteria; Volume 3 (2009), The Firmicutes; Volume 4 (2011), The Bacteroidetes, Spirochaetes, Tenericutes, Acidobacteria, Fibrobacteres, Fusobacteria, Dictyoglomi, Gemmatimonadetes, Lentisphaerae, Verrucomicrobia, Chlamydiae, and Planctomycetes; and Volume 5 (2012), The Actinobacteria.