Dry heat, Moist heat

3. • Nosocomial infections caused death in
10% of surgeries.
• Up to 25% mothers delivering in
hospitals died due to infection.

5. 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.

6. 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.

11. • Sunlight

12. • Drying

15.  red
hot

oxidation


22. 

23. 




24. Pasteurization,
Water Bath, Vaccine Bath, Inspissator.
Boiling
Koch /
Arnold’s Steamer, Tyndallization
Autoclave

26. Special vaccine bath

31. Tyndallisation /Intermittent Sterilization /
Fractional sterilization
• Principle – Vegetative cells & spores are killed
during the first heating & that the more resistent
spores subsequently germinate & are killed during
the second or the third heating.

32. Tyndallisation /Intermittent Sterilization /
Fractional sterilization
• Principle – Vegetative cells & spores are killed during the first
heating & that the more resistent spores subsequently germinate
& are killed during either the second or the third heating.
• Useful in sterilizing heat sensitive culture media containing
carbohydrates, egg or serum which are damaged by higher
temperature of autoclave.

34. –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.

36. –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

43. DEEP FILTERS
Name of Filter Made up of Examples Comments & Uses
Candle filters 1.Diatomaceous earth
2.Unglazed porcelain
Berkefeld filters
Chamberlain
filters
They are available in different porosity.
Mostly used for the purification of drinking water
and industrial uses.
Asbestos filters Asbestos (magnesium
silicate)
Seitz and
Sterimat filters
They have high adsorbing capacity and tend to
alkalinize the filtered fluid.
These are disposable , single use discs available
in different grades.
Asbestos is carcinogenic hence its use is
discouraged.
Sintered glass
filters
Fusing finely powdered
glass particles
They are expensive and brittle.
They have low absorptive property.
MEMBRANE FILTERS
Cellulose esters
Other polymers
They are routinely used for water purification
and analysis, sterilization, sterility testing and
solutions of parenteral use.
Wide range of average pore diameters(APD)
are available but 0.2mm size is widely used.

45. Non – Ionizing Radiation
Types Produced by Mode of action Uses Comments
Low energy
(Infrared and
ultraviolet rays)
UV lamps DNA damage Infrared rays:
Sterilization of prepacked items
such as syringes and catheters.
Ultraviolet rays:
Used for disinfecting operation
theaters and laboratories.
Use of UV light
is limited by
penetration and
hazardous.
Ionizing Radiation
High energy
ionizing type
(Gamma rays
and high
energy
electrons such
as X-rays and
cosmic rays)
Cobalt-60
based
instruments
DNA damage For the
sterilization of
antibiotics,
hormones and
other pre-
packed
disposable
items such as
catheters,
gloves,
syringes,
infusion sets,
oils, animal
feeds, etc.
They are expensive.
They are very effective due to
high penetrative power.