Lab Practical (PMF)

• What is essential for laboratory personnel to work safely?

  Knowledge of hazards and safety precautions
• Why is understanding the chain of infection important?

  It helps prevent infection transmission
• What does the CDC concept of Standard Precautions state?

  All human blood and body fluids are infectious
• What are the components of the chain of infection?

  • Infectious agents
  • Reservoir
  • Portal of exit
  • Mode of transmission
  • Portal of entry
  • Susceptible host
• What are major practices for biological hazard safety in the lab?

  Hand hygiene, PPE, and proper disposal
• What is the first step in handwashing?

  Stand in front of the sink
• How should hands be dried after washing?

  Dry hands well with a paper towel
• What is included in standard precautions for hand hygiene?

  Handwashing and alcohol-based antiseptics
• What should be done with contaminated materials?

  Dispose of them correctly
• What is the purpose of engineering controls in the lab?

  To minimize exposure to hazards
• What should be done with needles after use?

  Discard in sharps disposal containers
• What is the dilution formula?

  $DILUTION =$$\frac{amount \, of \, solute}{total \, volume}$
• What is the purpose of a serial dilution?

  To determine the concentration of antibodies
• How much diluent is needed for a 1:20 dilution?

  19 parts of diluent
• What is the endpoint in a serial dilution test?

  The last tube showing agglutination
• What is the main principle of the screening test for phagocytic engulfment?

  Mixing blood with bacterial culture
• What is the role of neutrophils in the immune response?

  They are important phagocytic cells
• What are the steps in the procedure for the screening test for phagocytic engulfment?

  1. Disinfect the working area
  2. Wear personal protective equipment
  3. Add heparinized blood to test tubes
  4. Add bacterial culture to each tube
  5. Incubate at room temperature
• What should be done if skin contact with a hazardous chemical occurs?

  Flush with water for 15 minutes
• What does the NFPA symbol indicate?

  Fire hazards of materials
• What information is included in an MSDS?

  Health hazards and emergency procedures
• What is the purpose of a Chemical Hygiene Plan?

  To detail safe laboratory practices
• What should be done with electrical equipment that is wet?

  Unplug and let dry completely
• What does the acronym RACE stand for in fire safety?

  Rescue, Alarm, Contain, Extinguish/Evacuate
• What agencies regulate the laboratory?

  • Clinical and Laboratory Standards Institute (CLSI)
  • The Joint Commission (TJC)
  • College of American Pathologists (CAP)
• What is the goal of the serial dilution experiment?

  To detect cold reacting antibodies
• What is the required blood volume for the phagocytic engulfment test?

  Minimum of 2ml Heparinized blood
• What is the purpose of incubating the test tubes in the phagocytic engulfment test?

  To allow bacteria to be engulfed by leukocytes
• How does the procedure for the screening test for phagocytic engulfment ensure accuracy?

  By using control test tubes for comparison
• What are the two types of leukocytes mentioned?

  Neutrophils and Macrophage
• What is the principle of the screening test for phagocytic engulfment?

  Mix blood with bacteria to observe engulfment
• What are the steps in the pre-analytical phase of the screening test?

  1. Disinfect the working area
  2. Wear Personal Protective Equipment
  3. Collect a minimum of 2ml Heparinized blood
• What materials are needed for the analytical phase of the screening test?

  • Broth culture of Bacillus subtilis or Staphylococcus epidermidis
  • Microscope slides
  • Pasteur pipettes
  • Rubber bulb
  • Test tubes
  • Wright’s stain
• What is the procedure for labeling test tubes in the screening test?

  1. Label three test tubes: Patient test tube (0 min, 15 min, 30 min) and Control test tube
• How many drops of buffer coat should be added to each test tube?

  4 to 8 drops
• What temperature should the tubes be incubated at?

  Room temperature or 37 °C
• What is the purpose of staining the slides with Wright’s stain?

  To visualize the cells and bacteria
• What are the steps in the Wright’s stain procedure?

  1. Cover smear with Wright’s stain for 5 minutes
  2. Add distilled water until it overflows
  3. Blow gently to mix
  4. Let buffer sit for 5 minutes
  5. Wash off with distilled water
  6. Air dry or blot with bibulous paper
• What should be done after preparing the smear on the glass slide?

  Examine microscopically with oil immersion
• What indicates a positive result in the screening test?

  Engulfment of bacteria demonstrated