Required Practical 6 Use of aseptic techniques to investigate the effect of antimicrobial substances on microbial growth.
What are aseptic techniques A level biology?
Aseptic techniques ensure the microorganisms being investigated do not escape or become contaminated with an unwanted microorganism. The growth of unwanted, pathogenic microorganisms is also prevented.
How many practicals do you need for A level biology?
Use of apparatus and techniques These apparatus and techniques are common to all A-level Biology specifications. Carrying out the 12 required practicals in section 8.2 means that students will have experienced use of each of these apparatus and techniques.
How do you investigate the effect of antimicrobial substances on microbial growth?
To investigate the effect of antimicrobial substances on bacteria, you can experiment using antibiotic discs and bacterial culture on agar plates.
How is Zone of Inhibition a level calculated biology?
Take a ruler or caliper that measures in millimeters and place the “0” in the center of the antibiotic disk. Measure from the center of the disk to the edge of area with zero growth. Take your measurement in millimeters. This measures the radius of the zone of inhibition.
What was the purpose of passing the neck of mccartney bottle through a blue Bunsen flame?
Flaming the neck of bottles and test tubes Passing the mouth of the bottle through a flame produces a convection current away from the opening, and helps to prevent contamination. The hot part of the flame is above the inner bright blue ‘cone’ and the vessel needs to be moved through the flame, not held in place.
What are 3 aseptic techniques?
- Sterile technique. The strictest form of aseptic technique, sterile technique is intended to provide a space that has no germs whatsoever.
- Surgical aseptic technique. This is a strict form of aseptic technique that can be used outside the operating room.
- Standard aseptic technique.
What is a bacteria lawn A level biology?
Bacterial lawn is a term used by microbiologists to describe the appearance of bacterial colonies when all the individual colonies on a Petri dish agar plate merge to form a field or mat of bacteria.
What are antimicrobials a level biology?
What is an antimicrobial agent? Antibiotics are a specific type of antimicrobial agent – they kill or limit the growth of microorganisms. Antimicrobial agents are not limited to antibiotics; chemicals like bleach or alcohol will kill bacteria, as will physical processes like heating or ionising radiation.
How do you do practical biology?
- Study pollen germination on a slide.
- Collect and study soil from at least two different sites and study them for texture,
- Collect water from two different water bodies around you and study them for pH,
- Study the presence of suspended particulate matter in air at two widely different.
How do you write a serial dilution a level biology?
How is practical endorsement assessed?
How is the practical endorsement externally assessed? The practical endorsement is assessed by visiting monitoring. The purpose of the visit is to ensure that the centre is implementing the requirements of the practical endorsement appropriately and applying the assessment criteria (CPAC) correctly.
How do bacteria become resistant to antibiotics A level biology?
There are two main ways that bacterial cells can acquire antibiotic resistance. One is through mutations that occur in the DNA of the cell during replication. The other way that bacteria acquire resistance is through horizontal gene transfer.
What is the most effective antimicrobial?
Sterilizers are the strongest type of public health antimicrobial product. In addition to bacteria, algae, and fungi, they also control hard-to-kill spores.
Is antimicrobial the same as antibiotic?
Antibiotics specifically target bacteria and are used to treat bacterial infections. On the other hand, antimicrobials encompass a broader range of products that act on microbes in general. Microbes encompass different types of organisms: bacteria, fungi, viruses, protozoa.
What factors affect zone of inhibition?
Factors influencing the size of inhibition zones in DDM and AMD include the size of the filter paper disk or hole, the amount of compound placed onto the disk or into the hole, the type and concentration of the agar, the thickness and pH of the medium, the microbial strain tested, and the incubation temperature.
How do you determine if the bacteria are resistant or sensitive to drugs?
The test is done by taking a sample from the infected site. The most common types of tests are listed below. A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial.
What does it mean if the zone of inhibition is large?
The size of the zone of inhibition is usually related to the level of antimicrobial activity present in the sample or product – a larger zone of inhibition usually means that the antimicrobial is more potent.
What are 4 common aseptic techniques?
According to The Joint Commission, there are four chief aspects of the aseptic technique: barriers, patient equipment and preparation, environmental controls, and contact guidelines. Each plays an important role in infection prevention during a medical procedure.
What are the 5 principles of aseptic technique?
These principles include the following: (1) use only sterile items within a sterile field; (2) sterile (scrubbed) personnel are gowned and gloved; (3) sterile personnel operate within a sterile field (sterile personnel touch only sterile items or areas, unsterile personnel touch only unsterile items or areas); (4) …
What are the 13 principles of sterile technique?
- Only sterile items are used within the sterile field.
- Sterile persons are gowned and gloved; gowns are sterile from table to chest level in front including sleeves to 2″ above the elbow.
- Tables are sterile only at table level.
- Sterile persons touch only sterile items or areas.
What’s the difference between aseptic and sterile technique?
Although aseptic and sterile both basically mean “germ-free,” sterile is more likely to describe medical environments, products, and instruments that have been cleaned (sterilized). Aseptic is more likely to describe techniques that keep an environment in its sterile state.
What is the purpose of Subculturing?
Subculturing, also referred to as passaging cells, is the removal of the medium and transfer of cells from a previous culture into fresh growth medium, a procedure that enables the further propagation of the cell line or cell strain.
What clean technique means?
Clean technique involves meticulous handwashing, maintaining a clean environment by preparing a clean field, using clean gloves and sterile instruments, and preventing direct contamination of materials and supplies. No “sterile to sterile” rules apply. This technique may also be referred to as non-sterile.
What is an example of a biofilm?
Plaque that forms on teeth is an example of a biofilm. Most bacteria are capable of forming biofilms. However, certain species have more of a disposition toward biofilms than others. In addition to plaque-forming bacteria on teeth, streptococci staphylococci, and lactobacilli also frequently form biofilms.