Autoclave, types of autoclave, horizontal autoclave, vertical autoclave, vacuum type autoclave, pressure cooker type autoclave. their purpose, precaution, etc....
Sterilization (or sterilisation) referring to any process that eliminates (removes) or kills (deactivates) all forms of life and other biological agents (such as prions, as well as viruses which some do not consider to be alive but are biological pathogens nonetheless), including transmissible agents (such as fungi, bacteria, viruses, prions, spore forms, unicellular eukaryotic organisms such as Plasmodium, etc.) present in a specified region, such as a surface, a volume of fluid, medication, or in a compound such as biological culture media
Autoclave, types of autoclave, horizontal autoclave, vertical autoclave, vacuum type autoclave, pressure cooker type autoclave. their purpose, precaution, etc....
Sterilization (or sterilisation) referring to any process that eliminates (removes) or kills (deactivates) all forms of life and other biological agents (such as prions, as well as viruses which some do not consider to be alive but are biological pathogens nonetheless), including transmissible agents (such as fungi, bacteria, viruses, prions, spore forms, unicellular eukaryotic organisms such as Plasmodium, etc.) present in a specified region, such as a surface, a volume of fluid, medication, or in a compound such as biological culture media
it is related with medical laboratory instrumentation and explains in very good way that what is hot air oven and its principle, working and all about it
The above PPT includes different methods of sterilization- Dry heat, Moist heat, Radiation and Chemical methods. It also includes principle and working of hot air oven and autoclave.
The physical factors affects the growth of microorganism.
1) Temperature
Temperature is the most important factor that influences the rate of enzyme catalysed reactions and rate of growth.
For every organisms there is an optimum temperature for growth and minimum temperature for inhibiting the growth.
Most extreme the microbes need liquid water to grow.(330C).
some algae and fungi grow at 55-60 degreeC.
Prokaryotes are grow at 100 degreeC.
Based on temperature the microorganisms are classified into two 4.
STERILISATION, PHYSICAL METHODS OF STERILISATION, METHODS OF STERILISATION, VARIOUS METHODS OF STERILISATION, AUTOCLAVES, HOT AIR OVEN, DRY HEAT STERILISATION, MOIST HEAT STERILISATION
it is related with medical laboratory instrumentation and explains in very good way that what is hot air oven and its principle, working and all about it
The above PPT includes different methods of sterilization- Dry heat, Moist heat, Radiation and Chemical methods. It also includes principle and working of hot air oven and autoclave.
The physical factors affects the growth of microorganism.
1) Temperature
Temperature is the most important factor that influences the rate of enzyme catalysed reactions and rate of growth.
For every organisms there is an optimum temperature for growth and minimum temperature for inhibiting the growth.
Most extreme the microbes need liquid water to grow.(330C).
some algae and fungi grow at 55-60 degreeC.
Prokaryotes are grow at 100 degreeC.
Based on temperature the microorganisms are classified into two 4.
STERILISATION, PHYSICAL METHODS OF STERILISATION, METHODS OF STERILISATION, VARIOUS METHODS OF STERILISATION, AUTOCLAVES, HOT AIR OVEN, DRY HEAT STERILISATION, MOIST HEAT STERILISATION
The availability of affordable, high quality, custom gene synthesis has greatly expanded what is possible for labs in numerous research areas. IDT offers a variety of gene synthesis solutions, including our revolutionary double-stranded gBlocks Gene Fragments. In this presentation, Dr Adam Clore discusses the many applications of gBlocks Gene Fragments, such as controls for qPCR and next generation sequencing, and donor templates for homology directed repair in CRISPR experiments. Learn more at www.idtdna.com/gblocks
Analyzing Fusion Genes Using Next-Generation SequencingQIAGEN
Fusion genes are hybrid genes formed by the fusion of two separate genes. Translocation, interstitial deletion and chromosomal inversions are some of the genetic events that can lead to the formation of fusion genes. The occurrence of fusion genes and its implications in cancer have already been known, but the emergence of NGS technology – especially RNA sequencing – offers the potential to detect novel gene fusions. You can learn more about fusion genes and applying NGS to detect them at our upcoming webinar, presented by Raed Samara, Ph.D., QIAGEN’s Global Product Manager for NGS technologies.
In this webinar, Dr. Raed Samara will cover:
1. Fusion genes: what they are and a historical perspective
2. Fusion gene detection: the current status
3. RNA sequencing vs. digital RNA sequencing
4. How to detect and accurately quantify novel fusion genes in your sample
STERILIZATION AND DISINFECTION BY DR RAHUL ACHARYA.pptrahulacharya52
sterilization using chemical methods, sterilization using physical methods, sterilization using sun light, heat, autoclave, hot air oven . tindalisation, inspisation .
At the end of this session learner will be able to:
Define Common terms.
Explain the importance of microorganisms control.
Discuss the Methods of sterilization.
Categorize the broad spectrum and narrow spectrum antibiotics.
Environmental health is the branch of public health concerned with all aspects of the natural and built environment affecting human health. In order to effectively control factors that may affect health, the requirements that must be met in order to create a healthy environment must be determined.[1] The major sub-disciplines of environmental health are environmental science, toxicology, environmental epidemiology, and environmental and occupational medicine.[2]
Definitions
WHO definitions
Environmental health was defined in a 1989 document by the World Health Organization (WHO) as: Those aspects of human health and disease that are determined by factors in the environment.[citation needed] It is also referred to as the theory and practice of accessing and controlling factors in the environment that can potentially affect health.[citation needed]
A 1990 WHO document states that environmental health, as used by the WHO Regional Office for Europe, "includes both the direct pathological effects of chemicals, radiation and some biological agents, and the effects (often indirect) on health and well being of the broad physical, psychological, social and cultural environment, which includes housing, urban development, land use and transport."[3]
As of 2016, the WHO website on environmental health states that "Environmental health addresses all the physical, chemical, and biological factors external to a person, and all the related factors impacting behaviours. It encompasses the assessment and control of those environmental factors that can potentially affect health. It is targeted towards preventing disease and creating health-supportive environments. This definition excludes behaviour not related to environment, as well as behaviour related to the social and cultural environment, as well as genetics."[4]
The WHO has also defined environmental health services as "those services which implement environmental health policies through monitoring and control activities. They also carry out that role by promoting the improvement of environmental parameters and by encouraging the use of environmentally friendly and healthy technologies and behaviors. They also have a leading role in developing and suggesting new policy areas."[5][6]
Other considerations
The term environmental medicine may be seen as a medical specialty, or branch of the broader field of environmental health.[7][8] Terminology is not fully established, and in many European countries they are used interchangeably.[9]
Children's environmental health is the academic discipline that studies how environmental exposures in early life—chemical, nutritional, and social—influence health and development in childhood and across the entire human life span.[10]
Other terms referring to or concerning environmental health include environmental public health and health protection.
Disciplines
Five basic disciplines generally contribute to the field of environmental health: environmental epidemiology,
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
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The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
2. Why we need Sterilization
• Microorganisms capable of causing
infection are constantly present in the
external environment and on the human
body.
• Microorganisms are responsible for
contamination and infection.
• The aim of sterilisation is to remove or
destroy them from materials or from
surfaces.
12/2/2012 Dr.T.V.Rao MD 2
3. How can microorganisms
be killed?
Denaturation of proteins (e.g. wet heat, ethylene
oxide)
Oxidation (e.g. dry heat, hydrogen peroxide)
Filtration
Interruption of DNA synthesis/repair (e.g.
radiation)
Interference with protein synthesis (e.g. bleach)
Disruption of cell membranes (e.g. phenols)
12/2/2012 Dr.T.V.Rao MD 3
4. Classification
There are two types of 2. Chemical sterilization
sterilization: physical and includes:
chemical. Alcohols
1. Physical sterilization Aldehydes
includes:
Phenolics
heat
Oxidizing agents
radiation
Quaternary ammonium
filtration compounds
ethylene oxide gas
Others
12/2/2012 Dr.T.V.Rao MD 4
5. Definitions:
Sterilisation :
– It is a process by which an article, surface or medium is
made free of all microorganisms either in vegetative or
spore form.
Disinfection :
– Destruction of all pathogens or organisms capable of
producing infections but not necessarily spores.
– All organisms may not be killed but the number is
reduced to a level that is no longer harmful to health.
12/2/2012 Dr.T.V.Rao MD 5
6. Antiseptics :
Antiseptics :
– Chemical disinfectants which can safely
applied to living tissues and are used to
prevent infection by inhibiting the growth
of microorganisms.
Asepsis :
– Technique by which the occurrence of
infection into an uninfected tissue is
prevented.
12/2/2012 Dr.T.V.Rao MD 6
7. Factors that influence efficacy of
disinfection/sterilization
Contact time
Physico-chemical environment (e.g. pH)
3 Presence of organic material
4 Temperature
5 Type of microorganism
6 Number of microorganisms
7 Material composition
12/2/2012 Dr.T.V.Rao MD 7
8. Uses of sterilisation:
1. Sterilisation of materials, instruments
used in surgical and diagnostic
procedures.
2. Sterilisation of Media and reagents
used in the microbiology laboratory.
3. Food and drug manufacturing to
ensure safety from contaminating
organisms.
12/2/2012 Dr.T.V.Rao MD 8
9. Understanding the Terminology
• a suffix indicating that the antimicrobial agent will kill or
• destroy a certain group of microorganism
• suffix “cide” – meaning to kill
• viricide – destroys virus
• fungicide – destroys fungi
• bactericide – destroys bacteria
•
• Suffix “static/stasis” – meaning to stand still
• a suffix indicating that the agent will prevent the growth or
• multiplication of the type of organism but are not killed outright
•
• bacteriostatic - prevents the growth of bacteria
• fungi static – prevents the growth of fungi
12/2/2012 Dr.T.V.Rao MD 9
10. Relative Resistance of Microbial
Forms
Highest resistance Moderate resistance Least resistance
bacterial endospore protozoan cyst most bacterial vegetative cells
(Bacillus & Clostridium) some fungal spores ordinary fungal spores & hypae
some naked virus enveloped virus
vegetative bacteria that Yeasts
have higher resistance Trophozoites
( M. tuberculosis, S.aureus,
Pseudomonas)
12/2/2012 Dr.T.V.Rao MD 10
11. What to sterilize?
• It is mandatory to sterilize :
– all instruments that penetrate soft tissues and bone.
– Instruments that are not intended to penetrate the
tissues, but that may come into contact with oral
tissues.
• If the sterilization procedure may damage the
instruments, then, sterilization can be replaced
by Disinfection procedure
12/2/2012 Dr.T.V.Rao MD
12. Ideal sterilization/disinfection process
• Highly efficacious
• Fast
• Good penetrability
• Compatible with all materials
• Non-toxic
• Effective despite presence of organic material
• Difficult to make significant mistakes in process
• Easily monitored
12/2/2012 Dr.T.V.Rao MD 12
13. Control of Microbial Growth:
Rate of Microbial Death
When bacterial populations are heated or treated
antimicrobial chemicals, they usually die at a
constant rate.
12/2/2012 Dr.T.V.Rao MD 13
14. Figure 9.1 A plot of microbial death rate
Number of living microbes
90% die Constant percentage
of the extant population
1 min is killed each minute
90% die
1 min
Time (min)
12/2/2012 Dr.T.V.Rao MD 14
19. How to Sterilize
Materials Method
1 Inoculating wires and loops Red heat
2 Glass ware- syringes, petridishes, testtubes, flasks Hot –air oven
etc.
3 Disposable syringes, and other disposable items Gamma radiation
4 Culture media Autoclaving
5 Culture media containing serum and egg Tyndallisation
6 Toxin , serum, sugar, and antibiotic solutions Filtration
7 Cystoscope and endoscope Glutaraldehyde
8 Infected soiled dressings Incineration
9 Skin Iodine, alcohol
12/2/2012 Dr.T.V.Rao MD 19
10 Milk Pasteurisation
20. Physical Methods of Microbial Control
Dry Heat:
Direct Flaming: Used to sterilize inoculating
loops and needles. Heat metal until it has a
red glow.
Incineration: Effective way to sterilize disposable
items (paper cups, dressings) and biological waste.
Hot Air Sterilization: Place objects in an oven.
Require 2 hours at 170oC for sterilization. Dry heat is
transfers heat less effectively to a cool body, than
moist heat.
12/2/2012 Dr.T.V.Rao MD 20
22. Physical Methods of Microbial Control
Moist Heat (Continued):
Pasteurization: Developed by Louis Pasteur to
prevent the spoilage of beverages. Used to
reduce microbes responsible for spoilage of
beer, milk, wine, juices, etc.
Classic Method of Pasteurization: Milk was
exposed to 65oC for 30 minutes.
High Temperature Short Time Pasteurization
(HTST): Used today. Milk is exposed to 72oC for 15
seconds.
12/2/2012 Dr.T.V.Rao MD 22
23. Inspissation:
1. Inspissation:
Heating at 80-85°C for half an hour daily on
three consecutive days
Serum or egg media are sterilised
2. Vaccine bath:
Heating at 60°C for an hour daily in vaccine
bath for several successive days.
Serum or body fluids can be sterilised by
heating at 56°C for an hour daily for several
successive days.
12/2/2012 Dr.T.V.Rao MD 23
24. Sun light:
• Sun light:
– Active germicidal
effect due to its
content of ultraviolet
rays .
– Natural method of
sterilisation of water
in tanks, rivers and
lakes.
12/2/2012 Dr.T.V.Rao MD 24
25. Heat :
• Factors influencing:
• Nature of heat
• Temperature and duration
• Characteristic of organism and
spores
• Type of material
12/2/2012 Dr.T.V.Rao MD 25
26. Heat effectively kills Majority of
Microbes
Heat :
• Principle:
– Dry heat kills the organism by
• denaturation of the bacterial proteins,
• oxidative damage
• toxic effect of elevated levels of
electrolytes.
12/2/2012 Dr.T.V.Rao MD 26
28. Dry-Heat Sterilization
• Involves heating at atmospheric pressure
and often use a fan to obtain uniform
temperature by circulation.
• Heat at 180º for half hour , 170º for 1 hr.,
or 160º C for 2 hrs.
• Times are the periods during which
object is maintained at the respective
temp.
12/2/2012 Dr.T.V.Rao MD
29. Dry heat:
• Dry heat:
1. Red heat:
Materials are held
in the flame of a
bunsen burner till
they become red
hot.
» Inoculating
wires or loops
» Tips of forceps
» Needles
12/2/2012 Dr.T.V.Rao MD 29
30. Dry heat:
• Dry heat:
2. Flaming: Materials are
passed through the
flame of a bunsen
burner without
allowing them to
become red hot.
» Glass slides
» scalpels
» Mouths of culture
tubes
12/2/2012 Dr.T.V.Rao MD 30
31. Incineration:
• Materials are
reduced to ashes by
burning.
• Instrument used was
incinerator.
• Soiled dressings
• Animal carcasses
• Bedding
12/2/2012 • Pathological material
Dr.T.V.Rao MD 31
32. Dry-Heat Sterilization
Disadvantages
• Disadvantages:
–Less reliable than autoclaving
–Large temp difference may arise within
device.
–sharp instruments get dulled
–Many materials do not tolerate dry heat
12/2/2012 Dr.T.V.Rao MD
33. Hot air oven:
• Most widely used method
• Electrically heated and fitted with a fan to
even distribution of air in the chamber.
• Fitted with a thermostat that maintains
the chamber air at a chosen temperature.
• Temperature and time:
» 160 C for 2 hours.
» 170 C for 1 hour
» 180 C for 30 minutes.
12/2/2012 Dr.T.V.Rao MD 33
34. Uses of Hot Air Oven
– Sterilisation of
1.Glassware like glass syringes, petri
dishes, pipettes and test tubes.
2.Surgical instruments like scalpels,
scissors, forceps etc.
3.Chemicals like liquid paraffin, fats
etc.
12/2/2012 Dr.T.V.Rao MD 34
35. – Precautions :
1. Should not be overloaded
2. Arranged in a manner which allows free
circulation of air
3. Material to be sterilized should be perfectly dry.
4. Test tubes, flasks etc. should be fitted with
cotton plugs.
5. petridishes and pipetts should be wrapped in
paper.
6. Rubber materials and inflammable materials
should not be kept inside.
7. The oven must be allowed to cool for two hours
before opening, since glass ware may crack by
12/2/2012 sudden cooling. Dr.T.V.Rao MD 35
39. A temperature at 100°C
II. A
temperature
at 100°C
1. Boiling
2. Tyndallisation
3. Steam
sterilisation
12/2/2012 Dr.T.V.Rao MD 39
40. Boiling :
1 Boiling for 10 – 30 minutes may kill most of
vegetative forms but spores with stand boiling.
2. Tyndallisation :
Steam at 100C for 20 minutes on three
successive days
Used for egg , serum and sugar containing
media.
3. Steam sterilizer :
Steam at 100°C for 90 minutes.
Used for media which are decomposed at high
temperature.
12/2/2012 Dr.T.V.Rao MD 40
41. Temperatures above 100°C
III. A temperature
above 100°C
Autoclave :
-Steam above
100°C has a
better killing
power than
dry heat.
-Bacteria are
more
susceptible to
moist heat.
12/2/2012 Dr.T.V.Rao MD 41
42. Components of autoclave:
• Components of autoclave:
– Consists of vertical or horizontal cylinder of
gunmetal or stainless steel.
– Lid is fastened by screw clamps and
rendered air tight by an asbestos washer.
– Lid bears a discharge tap for air and steam,
a pressure gauge and a safety valve.
12/2/2012 Dr.T.V.Rao MD 42
46. Sterilisation conditions
• Sterilisation conditions:
–Temperature – 121 °C
–Chamber pressure -15 lb per square
inch.
–Holding time – 15 minutes
–Others :
• 126°C for 10 minutes
• 133°C for 3 minutes
12/2/2012 Dr.T.V.Rao MD 46
47. Sterilization – instrument Packing
• Often instruments are packed for sterilization to
be stored and handled without being
contaminated.
• Packing depend on the intended shelf life after
sterilization.
• The available packing options are:
– Textile has shelf life of 1 month
– Paper has shelf life of 1 – 6 months
– Nylon, glass, and metal have shelf life of 1 year if
tightly closed
12/2/2012 Dr.T.V.Rao MD
48. Uses of Autoclaves:
• Uses :
1. Useful for
materials which
can not withstand
high temp.
2. To sterilize culture
media, rubber
material, gowns,
dressings, gloves
etc.
12/2/2012 Dr.T.V.Rao MD 48
50. Sterility Controls
Yellow medium
means spores are
Cap that allows viable; autoclaved
steam to penetrate objects are not
sterile.
Flexible plastic
vial
Crushable glass Incubation
ampule
Nutrient medium
containing pH
color indicator Red medium
means spores were
After autoclaving, flexible killed; autoclaved
Endospore strip
vial is squeezed to break objects are
ampule and release sterile.
medium onto spore strip.
12/2/2012 Dr.T.V.Rao MD 50
51. Filtration:
• . Filtration:
• Useful for substances which get
damaged by heat.
• To sterilize sera, sugars and antibiotic
solutions.
• To obtain bacteria free filtrates of
clinical samples.
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• Purification of water.
Dr.T.V.Rao MD 51
52. FILTRATION STERILIZATION
This method is commonly used for To ensure sterility, the filtration
sensitive pharmaceuticals and protein system must be tested to ensure that
solutions in biological research. the membranes have not been
A filter with pore size 0.2 µm will punctured prior to or during use.
effectively remove bacteria. To ensure the best results,
If viruses must also be removed, a pharmaceutical sterile filtration is
much smaller pore size around 20 nm performed in a room with highly
is needed. filtered air (HEPA filtration) or in a
Prions are not removed by filtration. laminar flow cabinet or "flowbox", a
device which produces a laminar
The filtration equipment and the stream of HEPA filtered air.
filters themselves may be purchased
as presterilized disposable units in HEPA filters are critical in the
sealed packaging, prevention of the spread of airborne
bacterial and viral organisms and,
or must be sterilized by the user, therefore, infection. Typically,
generally by autoclaving at a medical-use HEPA filtration systems
temperature that does not damage also incorporate high-energy ultra-
the fragile filter membranes. violet light units to kill off the live
bacteria and viruses trapped by the
filter media.
53. Several Types of Filters
• Types of filters:
1. Candle filters
2. Asbestos disc filters
3. Sintered glass filters
4. Membrane filters
5. Air filters
6. Syringe filters
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54. Filtration
Sterilize solutions
that may be
damaged or
denatured by high
temperatures or
chemical agents.
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55. The filtering Depends on Pore Size
The pore size for filtering bacteria,
yeasts, and fungi is in the range of
0.22-0.45 μm (filtration membranes
are most popular for this purpose).
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62. Physical Methods of Microbial
Control:
Radiation: Three types of radiation kill
microbes:
Ultraviolet light (Nonionizing Radiation): Wavelength
is longer than 1 nanometer. Damages DNA by producing
thymine dimers, which cause mutations.
Used to disinfect operating rooms, nurseries,
cafeterias.
Disadvantages: Damages skin, eyes. Doesn’t penetrate
paper, glass, and cloth.
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63. Non-Ionising radiation:
1. Infra red rays
2. Ultraviolet (UV) rays
– Infra red is used for rapid mass sterilisation of
syringes and catheters.
– Ultraviolet radiation is used for disinfecting
enclosed areas such as bacterial laboratory,
inoculation hood, laminar flow and operation
theatres.
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64. Programme Created by Dr.T.V.Rao MD
for Medical and Paramedical Students
Email
doctortvrao@gmail.com
12/2/2012 Dr.T.V.Rao MD 64