Basic Microbiology Techniques - Sterilization

<p>It destroys enzymes faster in a hydrated state (C)</p> Signup and view all the answers

<p>Pasteurization (D)</p> Signup and view all the answers

<p>Microbiostatic agents inhibit growth but do not kill (A)</p> Signup and view all the answers

<p>It destroys vegetative cells of pathogens at 100°C for 20 minutes (B)</p> Signup and view all the answers

<p>It is a physical method of sterilization (D)</p> Signup and view all the answers

<p>121°C at 15 psi (B)</p> Signup and view all the answers

<p>Liquid culture media (D)</p> Signup and view all the answers

<p>Denaturation and lysis of proteins (A)</p> Signup and view all the answers

<p>It provides moisture necessary for killing microbes. (A)</p> Signup and view all the answers

<p>170°C for 30 min (B)</p> Signup and view all the answers

<p>Autoclaves ensure complete sterility by using steam under pressure. (A)</p> Signup and view all the answers

<p>It does not rely on moisture that can affect oily substances. (D)</p> Signup and view all the answers

<p>It increases the boiling point. (A)</p> Signup and view all the answers

<p>Sterilization of heat-sensitive liquids (A)</p> Signup and view all the answers

<p>Pressure-operated filtration (B)</p> Signup and view all the answers

<p>Mechanical sterilization (A)</p> Signup and view all the answers

<p>Biological (D)</p> Signup and view all the answers

<p>Sterile (C)</p> Signup and view all the answers

<p>To remove microorganisms (C)</p> Signup and view all the answers

<p>Red heat (A)</p> Signup and view all the answers

<p>Ability to penetrate small openings (B)</p> Signup and view all the answers

<p>Low level of contamination is present (C)</p> Signup and view all the answers

<p>Release of toxic gases (B)</p> Signup and view all the answers

<p>Infrared (A)</p> Signup and view all the answers

<p>Boiling (B)</p> Signup and view all the answers

<p>Effectiveness in penetrating materials (B)</p> Signup and view all the answers

<p>To act as a disinfecting agent (A)</p> Signup and view all the answers

<p>20-24 hours (D)</p> Signup and view all the answers

<p>It is corrosive to metallic equipment (D)</p> Signup and view all the answers

<p>It removes rather than destroys microorganisms (A)</p> Signup and view all the answers

<p>Bacteria and larger particles (D)</p> Signup and view all the answers

<p>Clarification of liquids and gases (A)</p> Signup and view all the answers

<p>Filtering and trapping within the matrix of the filter material (C)</p> Signup and view all the answers

<p>It oxidizes organic compounds (C)</p> Signup and view all the answers

<p>It is more effective at lower temperatures. (B)</p> Signup and view all the answers

<p>Ionising radiation (B)</p> Signup and view all the answers

<p>It is blocked by glass, water, and dirt. (C)</p> Signup and view all the answers

<p>Powders and oils (A)</p> Signup and view all the answers

<p>It causes abnormal bond formation. (C)</p> Signup and view all the answers

<p>180°C for 8 minutes (A)</p> Signup and view all the answers

<p>It causes mutations in cell organelles. (B)</p> Signup and view all the answers

<p>Moist heat sterilization (C)</p> Signup and view all the answers

A microbial control method that completely eliminates all microbial life, including endospores.

A microbial control method that reduces the number of pathogenic microorganisms to a safe level.

A physical method of sterilization using steam under pressure.

A physical method of sterilization using high temperatures in air (with low moisture content).

A moist heat method that kills vegetative cells of pathogens but not endospores, not sterilizing.

A heat treatment to kill most vegetative cells of pathogens in food products.

A microbial control method that kills microbes.

A microbial control method that inhibits microbial growth without killing them.

A moist heat sterilization method using steam under pressure to kill all microorganisms, including endospores.

121°C at 15 PSI pressure for 15 minutes.

An oven used for sterilization by dry heat. Various temperatures and durations are needed

Highly resistant, dormant bacterial structures that can survive harsh conditions and are difficult to destroy.

The use of chemical agents to kill microorganisms and achieve sterilization.

Sterilization by exposing objects to a gas like ethylene oxide in a closed chamber.

Sterilization by submerging objects in a liquid sterilizing agent like alcohol or bleach.

Gaseous sterilization is more effective than liquid sterilization because gases can penetrate tiny spaces and openings, leading to better results.

Liquid sterilization is less effective than gaseous sterilization but is suitable for situations with low contamination levels.

Chemical sterilization is used for materials that are sensitive to heat, like plastics, fiber optics, and biological specimens.

Gaseous sterilization releases toxic gases that need to be removed regularly from the system.

Using UV light (around 260nm) to damage DNA, causing mutations and preventing microbes from replicating.

Using X-rays, gamma rays, or high-speed electrons to damage DNA, cell organelles, and generate toxic substances.

Using infrared radiation to generate heat, killing microbes by raising the temperature of materials.

A method using an infrared tunnel where instruments and glassware are moved through a controlled environment, exposed to infrared radiation.

Sterilization eliminates all microbial life, including endospores, while disinfection reduces pathogenic microorganisms to a safe level.

Effective for sterilizing surfaces, air, and water, commonly used in biological safety cabinets (BSC).

A method of sterilization where liquids or gases are passed through a membrane filter with pores small enough to trap microorganisms, rendering the filtrate sterile.

This method is commonly used for sterilizing heat-sensitive liquids like injections, ophthalmic solutions, as well as air and gases for sterile environments.

These filters are available in various configurations, including pressure-operated filter holders for syringes, in-line use, and vacuum filtration towers for larger liquid volumes.

Filtration under pressure is generally considered the most suitable method for membrane filtration, as it ensures efficient and consistent removal of microorganisms.

The liquid or gas that passes through the membrane filter is considered sterile after filtration, free of any microorganisms.

A common disinfecting agent, often referred to as bleach. It works by oxidizing organic compounds and can kill some pathogens when submerged for a short period but requires 20-24 hours to reach sterilization.

A method that physically removes microorganisms from a solution by passing it through a filter with pores that are too small for microbes to pass through.

Membrane filtration is a mechanical method. It removes microorganisms without destroying them.

Advantages of membrane filtration include: 1. It effectively removes both living microbes and non-living particles. 2. It can be used for both liquids and gases. 3. It's gentle on heat-sensitive substances.

Membrane filtration works by trapping microbes within the matrix of a filter with tiny pores. The liquid can pass through, but the microbes are too large to fit.

Hypochlorite is corrosive to metallic equipment.

Hypochlorite can be used for disinfection of workstations, surfaces, and even cleaning blood spills.