Sometimes called methods or procedures, protocols are “recipes” that researchers use to recreate experiments in their laboratory. They provide predefined written procedural methods in the design and implementation of experiments including bias, safety, equipment, statistical methods, reporting and troubleshooting.
(Above) A swannecked flask is pictured with broth and no bacteria in it after being boiled to remove any germs or microorganisms. (Below) Another swannecked flask is pictured with outside contaminants in the air allowed in. This broth grows microorganisms.
Figure used with permission of the copyright holder: http://commons.wikimedia.org/wiki/File:Experiment_Pasteur_English.jpg