Because microbiology can take many different approaches, the number of scientists who have made contribution to microbiology is very extensive. The Golden Age of Microbiology was the 1800s; and discoveries were related to industrial and medical observations of practices found in the 19^th Century.

Microbiologists are very curious; and the hard work of these scientists for the past 300 years has added much to our knowledge of microbes. Each discovery often led to more questions and expansion of the knowledge base. In the 1500s, Janssen who was a Dutch maker of eyeglasses invented a compound microscope; and an Italian physician (Fracastoro) suggested that invisible organisms might cause disease.

In 1796, Edward Jenner introduced a vaccination for smallpox. Later examples of vaccine development include rabies in 1885 by Louis Pasteur and polio in 1954 by Jonas Salk.

In 1929 Alexander Fleming discovered the antibiotic penicillin. Howard Florey and Ernst Chain developed commercial methods of producing penicillin in 1941 which put penicillin into widespread use during World War II. England was in constant danger of bombings so pharmaceutical companies like Squibb, Merck-Sharpe-Dohme, and Eli Lilly became major manufacturers of antibiotics in the United States. Other antibiotics like streptomycin were discovered in 1944 by Selman Waksman.

Modern aseptic techniques have come a long way since Ignaz Semmelweiss first beleived in 1847 that "dirty hands" of physicians were responsible for the illnesses contracted by mothers of newborn babies. In 1867 Joseph Lister used carbolic acid (phenol) spray to reduce microbes and infections during surgery. A filthy lab coat may have been the sign of a busy doctor, but not necessarily a good doctor who understands the importance of aseptic technique.

The study of microbes in the laboratory has been made more valuable through the creative observations and minds of many scientists. Many bacteria lack pigments or color so separation of similar bacteria was made easier by the differential staining technique developed by Hans Gram in 1884. Julius Petri made a special dish in 1887; this dish held media and permitted the observation of microbe colonies (growths) on the food. Fanny Hesse introduced agar to solidify media in 1881.

Since the early 1970s great progress has been made regarding recombinant DNA, DNA inserting, and other bio-engineering techniques. Scientists involved in these new microbiological activities include Berg, Kaiser, Cohen, and Boyer.