Knowledge (XXG)

Moist heat sterilization

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153:. When sterilizing in this way, samples are placed into a steam chamber on a shelf or raised floor, and the chamber is closed and heated so that steam forces air out of the vents or exhausts. Pressure is then applied so that the interior temperature reaches 121 °C (250 °F), and this temperature is maintained for between 15 and 30 minutes. This elevated temperature and pressure is sufficient to sterilize samples of any commonly encountered microbes or spores. The chamber is then allowed to cool slowly or by passive heat dissipation; it is rare for forced cooling to be applied, or for pressure to be vented deliberately. Pressure sterilization is the prevailing method used for medical sterilization of heat-resistant tools, and for sterilization of materials for microbiology and other fields calling for 137:, which uses three successive steam treatments to achieve sterilization over the course of three days. This works by killing vegetative cells, allowing germination of surviving spores, and killing the resulting vegetative cells before they have time to form further spores. Any surviving spores from the first treatment, or incidentally formed spores during the first incubation period, are killed in a third steaming cycle. 109:
are sterilized alongside a standard load, and are then incubated in sterile media (often contained within the sample in a glass ampule to be broken after sterilization). A color change in the media (indicating acid production by bacteria; requires the medium to be formulated for this purpose), or the
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may be employed. Flash techniques generally run for the minimum time, temperature, or pressure, and may sacrifice some safeguards, such as the abilities to validate with biological indicators or prevent contamination. Additional protocols are generally taken to mitigate the sacrifices; flash
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To facilitate efficient sterilization by steam and pressure, there are several methods of verification and indication used; these include color-changing indicator tapes and biological indicators. When using biological indicators, samples containing spores of heat-resistant microbes such as
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of macromolecules, primarily proteins. Destruction of cells by lysis may also play a role. While "sterility" implies the destruction of free-living organisms which may grow within a sample, sterilization does not necessarily entail destruction of infectious matter.
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techniques that use hot water vapor as a sterilizing agent. Heating an article is one of the earliest forms of sterilization practiced. The various procedures used to perform moist heat sterilization process cause destruction of micro-organisms by
114:(cloudiness indicating light scattering by bacterial cells) indicates that sterilization was not achieved and the sterilization cycle may need revision or improvement. 63:
practiced. Moist heat sterilization processes sterilize using hot air that is heavily laden with water vapor, which plays the most important role in the sterilization.
169:, steam-penetrative protective packaging may be used to prepackage items, and specially designed rigid sterilization container systems can be reused. 343: 289: 232: 318: 60: 43: 31: 106: 88: 48: 321:. National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Centers for Disease Control and Prevention. 178: 338: 96:
are an example of an infectious agent that can survive sterilization by moist heat, depending on conditions.
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shortly thereafter and resume growth. Therefore, boiling is an insufficient method to achieve sterilization.
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A more commonly used method when extended heat is not a concern is to use an
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sterilization equipment is often kept in an operating room's
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In cases when items need to be sterilized for immediate use,
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Ananthanarayan; Panikar (1940), "Textbook of Microbiology",
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Division of Healthcare Quality Promotion (DHQP) (2008).
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a sample for 30 minutes or more will kill virtually all
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Prof. C P Baveja (1940), "Textbook of Microbiology",
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Moist heat causes destruction of micro-organisms by
59:Heating an article is one of the earliest forms of 253: 251: 8: 312: 310: 308: 279: 222: 196: 194: 37: 190: 7: 25: 71:cells present, but will not kill 107:Geobacillus stearothermophilis 1: 344:Sterilization (microbiology) 32:Sterilization (microbiology) 133:A more effective method is 360: 126: 29: 179:Sterility assurance level 83:Action on micro-organisms 27:Sterilization technique 319:"Flash Sterilization" 272:1940Natur.146..149H 215:1940Natur.146..149H 162:flash sterilization 51:of macromolecules. 40:heat sterilization 155:aseptic technique 16:(Redirected from 351: 323: 322: 314: 303: 302: 283: 281:10.1038/146149a0 255: 246: 245: 226: 224:10.1038/146149a0 198: 39: 21: 359: 358: 354: 353: 352: 350: 349: 348: 339:Medical hygiene 329: 328: 327: 326: 316: 315: 306: 292: 257: 256: 249: 235: 200: 199: 192: 187: 175: 151:pressure cooker 143: 131: 125: 120: 102: 85: 57: 34: 28: 23: 22: 15: 12: 11: 5: 357: 355: 347: 346: 341: 331: 330: 325: 324: 304: 290: 247: 233: 189: 188: 186: 183: 182: 181: 174: 171: 142: 139: 135:Tyndallization 129:Tyndallization 127:Main article: 124: 123:Tyndallization 121: 119: 116: 110:appearance of 101: 98: 84: 81: 56: 53: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 356: 345: 342: 340: 337: 336: 334: 320: 313: 311: 309: 305: 301: 297: 293: 291:81-250-2808-0 287: 282: 277: 273: 269: 266:(3692): 149, 265: 261: 254: 252: 248: 244: 240: 236: 234:81-7855-266-3 230: 225: 220: 216: 212: 209:(3692): 149, 208: 204: 197: 195: 191: 184: 180: 177: 176: 172: 170: 168: 167:sterile field 163: 158: 156: 152: 148: 141:High pressure 140: 138: 136: 130: 122: 117: 115: 113: 108: 99: 97: 95: 90: 82: 80: 78: 74: 70: 66: 62: 61:sterilization 54: 52: 50: 45: 44:sterilization 41: 33: 19: 263: 259: 206: 202: 161: 159: 144: 132: 118:Methods used 103: 89:denaturation 86: 75:, which can 58: 49:denaturation 36: 35: 55:Description 333:Categories 185:References 100:Validation 69:vegetative 42:describes 30:See also: 18:Moist heat 147:autoclave 112:turbidity 77:germinate 300:37953413 243:37953413 173:See also 268:Bibcode 211:Bibcode 65:Boiling 298:  288:  260:Nature 241:  231:  203:Nature 94:Prions 73:spores 296:S2CID 239:S2CID 38:Moist 286:ISBN 229:ISBN 276:doi 264:146 219:doi 207:146 149:or 335:: 307:^ 294:, 284:, 274:, 262:, 250:^ 237:, 227:, 217:, 205:, 193:^ 157:. 278:: 270:: 221:: 213:: 20:)

Index

Moist heat
Sterilization (microbiology)
sterilization
denaturation
sterilization
Boiling
vegetative
spores
germinate
denaturation
Prions
Geobacillus stearothermophilis
turbidity
Tyndallization
Tyndallization
autoclave
pressure cooker
aseptic technique
sterile field
Sterility assurance level


Bibcode
1940Natur.146..149H
doi
10.1038/146149a0
ISBN
81-7855-266-3
S2CID
37953413

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