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Heat fixation is used for the fixation of single cell organisms, most commonly bacteria and archaea. The organisms are typically mixed with water or physiological saline which helps to evenly spread out the sample. Once diluted, the sample is spread onto a microscope slide. This diluted bacteria sample is commonly referred to as a smear after ...
Prior to the development of more efficient methods, this stain was performed using the Wirtz method with heat fixation and counterstain. Through the use of malachite green and a diluted ratio of carbol fuchsin, fixing bacteria in osmic acid was a great way to ensure no blending of dyes.
Moist heat sterilization processes sterilize using hot air that is heavily laden with water vapor, which plays the most important role in the sterilization. [ 1 ] [ 2 ] Boiling a sample for 30 minutes or more will kill virtually all vegetative cells present, but will not kill spores , which can germinate shortly thereafter and resume growth.
Applying a primary stain (crystal violet) to a heat-fixed smear of a bacterial culture. Heat fixation kills some bacteria but is mostly used to affix the bacteria to the slide so that they do not rinse out during the staining procedure. The addition of iodine, which binds to crystal violet and traps it in the cell
Dry heat sterilizer. Dry heat was the first method of sterilization and is a longer process than moist heat sterilization. The destruction of microorganisms through the use of dry heat is a gradual phenomenon. With longer exposure to lethal temperatures, the number of killed microorganisms increases.
The Kinyoun method can be modified as a weak acid fast stain, which uses 0.5–1.0% sulfuric acid instead of hydrochloric acid.The weak acid fast stain, in addition to staining Mycobacteria, will also stain organisms that are not able to maintain the carbol fuchsin after decolorizing with HCl, such as Nocardia species and Cryptosporidium.
Heat stabilization is an additive-free preservation technology for tissue samples which stops degradation and changes immediately and permanently. Heat stabilization uses rapid conductive heating, under controlled pressure, to generate a fast, homogeneous and irreversible thermal denaturation of proteins, resulting in a complete and permanent elimination of all enzymatic activity that would ...
Dry heat sterilization of an object is one of the earliest forms of sterilization practiced. It uses hot air that is either free from water vapor or has very little of it, where this moisture plays a minimal or no role in the process of sterilization.