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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 ...
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.
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.
The cell wall's strength is enhanced by teichoic acids, glycopolymeric substances embedded within the peptidoglycan. Teichoic acids play multiple roles, such as generating the cell's net negative charge, contributing to cell wall rigidity and shape maintenance, and aiding in cell division and resistance to various stressors, including heat and ...
Ultra-high temperature processing (UHT), ultra-heat treatment, or ultra-pasteurization [1] is a food processing technology that sterilizes liquid food by heating it above 140 °C (284 °F) – the temperature required to kill bacterial endospores – for two to five seconds. [2]
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.
Tyndallization is a process from the nineteenth century for sterilizing substances, usually food, named after its inventor John Tyndall, that can be used to kill heat-resistant endospores. Although now considered dated, it is still occasionally used. [citation needed]
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.