Microbiology uses the same practical research methods as any other advanced (technologically empowered) science. General Exploratory research in the field of science during the late 1700's and early 1800's led to differentiation across the table, creating such various fields as biology, chemistry and physics within the natural sciences. Biologically speaking, chemistry has allowed us to grasp the cellular biological level of life to such a degree that microbiology was then necessarily developed as a field.
There is also a difference between constructive research which develops and answer to a problem, such as how do we take the bacteria out of milk (with the answer being pasteurization), and that of free and open research, whereby a scientists simply examines phenomenological nature itself and draws conclusions about the behavioral components of natures in action. One the one hand, constructivism compels you to find and answer to a given problem, whereby open research (i.e. discovery) provides you with on hand understandings with which you can later use to attribute solutions to problems that fit the solved criteria.
Another classification of research categories is such that of the primary and secondary types. Primary research, often referred to as field research is such that it represents first hand evidence or research that has been gathered straight from out of reality, or nature itself. Secondary research, on the other hand, is that which, already represented within physical mediums, (i.e. books, papers reports) is now made available to assist in the discovery and understanding of the various fields to which it is applied.
Listed above is a New York Public Library Research room, whereby research can be carried out using many resources, provided the only type of research needed is of the secondary variety.
Other types of research include Qualitative Research, which refers to the aspect of determining the qualities of a given function or entity, vrs Quantitative Research, which refers to the measurement of a function's or entity's basic physical constituents such as mass, volume, height and so on.