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Definition
| killing microorganisms by denaturing proteins and oxidation (burning) of vital structural and metabolic chemicals. |
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Definition
| Dry heat method. Passing tube or loop through flame |
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Term
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Definition
| circulate hot air, 171 degrees C for 1 hour, or 160 degrees C for 2 hours. Good for glass, metal, oil and powders. Some materials, like paper and plastic cannot be sterilized this way without being destroyed. |
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Term
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Definition
| kills microbes primarily by denaturing proteins, but can damage cell membranes, and nucleic acids. |
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Term
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Definition
| 100 deg C. Kills most vegetative cells but does not kill endospores. |
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Term
| Tyndallization (Intermittent or Fractional Sterilization) |
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Definition
| 100 deg C steam for 30 mins or boiling for 30 mins. requires heating the material on three successive days and incubation in between. This will allow for the germination of spores, which get killed in the following treatment. |
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Definition
| Steam heat under pressure. Most reliable way of sterilization. Standard pressure is 15 PSI, 121 deg C for 15 mins. |
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Definition
| used in processing milk products, fruit juices, beer and wine. Kills vegetative pathogens and some microbes involved in food spoilage. |
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Term
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Definition
| cold-loving organisms (0-20 deg C) |
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Term
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Definition
| Middle-loving organisms (temperature). Body temp 37 deg C. |
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Term
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Definition
| Heat loving. 40-70 deg C. |
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Definition
| Extreme heat loving. 80+ deg C. |
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Term
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Definition
| hydrogen ion concentration |
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Definition
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Definition
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Definition
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Term
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Definition
Method used to determine the number of bacteria in food and water. Make dilutions of sample in sterile water until we get between 30-300 colony forming units (CFU) growing on a plate.
CFU x Dil. Factor - #CFU/gram of substance tested |
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Term
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Definition
| Organisms which are only in or on the body for a short time and do not become established onthe body. Do not cause diseases. |
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Term
| Normal or Resident Flora/Microbiota |
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Definition
| Organisms which colonize the body in a symbiotic relationship that is commensalistic or mutalistic (Mutualism: a mutually beneficial relationship, both organisms are benefited. Commensalism: one organism is benefited and the other is neither benefited nor harmed.) |
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Term
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Definition
| Do not normally cause disease in healthy immunocompetent individuals but under certain conditions they can cause disease. |
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Definition
| Disease causing organisms. |
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Term
| Resolution or Resolving Power |
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Definition
| the shortest distance two objects can be apart and still be seen as separate (modern microscopes can distinguish between objects that are 0.2 micrometers apart). |
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Term
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Definition
| Rainbows and halos that are seen around microscopic specimen when white like is used. |
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Term
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Definition
Mathematical function referring to the ability of the lens to gather light. Better N.A. = better resolution.
Factors that affect NA:
- quality of lenses
- condenser lens
- refractive index
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Term
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Definition
| controls the amount of light entering the objective lens |
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Term
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Definition
| The relative velocity with which light passes through one substance compared to another. If substances have different refractive indices light passing through both substances will be refracted at the boundary between the substances. This is the reason we use oil on 100x obj. lens - it has almost the same refractive index as glass. |
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Term
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Definition
| Minimal focusing is needed when switching from one objective lens to the next. |
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Definition
| The distance between the slide and the objective lens when the specimen is in focus. |
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Definition
| A culture that contains only one type of organism. Technically, in a pure culture all the cells are the progeny (offspring) of a single cell. |
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Term
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Definition
| A solid agar plate is divided into four quadrants. A loop is used to deposit the specimen onto the first quadrant. The loop is flamed and is drag through part of the first quadrant to pick up cells and drawn into the next quadrant. This is repeated until quadrant four has, ideally, only a few, isolated cells. |
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