BIOS 242 Week 5 Assignment; Lab 9 of 14 Onsite; Food Safety.
Lab 9: Food Safety
Learning Objectives:
To learn about effectiveness of hand washing
To learn about cleaning produce
To learn about appropriately storing foods
GI infections occur due to contaminated food and water. Clean drinking...
BIOS242, Week 5, Lab 1
Name:
1Lab 9: Food Safety
Learning Objectives:
•To learn about effectiveness of hand washing
•To learn about cleaning produce
•To learn about appropriately storing foods
GI infections occur due to contaminated food and water. Clean drinking water, washed produce, appropriate storage of food and simple personal hygiene habits such as hand washing help tremendously
in reducing the incident of GI infections. In this lab, we will test the effectiveness of some of these practices.
Note: Use personal protective equipment (PPE) at all times. Follow instructions at all times. After overnight growth, seal the plates with parafilm. Do not open the plates.
Exercise 1: Personal Hygiene- Importance of Hand washing Materials:
Nutrient agar, ruler, marker, hand soap, paper towel
Method:
1.Obtain a nutrient agar plate.
2.Use a marker and a ruler to divide the back of the agar plate in half. Mark each half as “Before Washing” and “After Washing”.
3.Slightly open the “Before Washing” section of the plate and without washing your hands, gently
touch your index finger on the agar plate for approximately 3 seconds.
a.Do not press too hard to disturb the agar
b.Gently touch your finger to agar, there is no need to press
4.Wash your hands thoroughly with soap and water.
5.Gently bloat dry your hands using paper towel.
6.Slightly open the “After Washing” section of the plate and gently touch your index finger on the agar plate for approximately 3 seconds.
7.Keep the plates in incubator at 37◦C for 24 hours.
8.During the next lab meeting, count the colonies grown in each of the sections of your plate. If it is more than 100 colonies, write TNTC (Too numerous to count) in the report.
9.Write your observations in Lab report.
10.Once observation is completed, immediately put the plates in appropriate waste container for autoclaving.
Exercise 2: Food safety- Effectiveness of washing produce Materials:
Nutrient agar, sterile swab, marker, celery or lettuce or any other leafy greens, paper towel
Method: BIOS242, Week 5, Lab 1
Name:
21.Obtain a nutrient agar plate.
2.Use a marker to divide the plate in half. Mark each half as “Before Washing” and “After Washing”.
3.Obtain a sterile swab and without washing the produce given by instructor, swab its surface.
4.Slightly open the “Before Washing” section of the plate and gently streak the agar plate. Be careful not to disturbed the agar.
5.Wash the produce thoroughly using sufficient water.
6.Gently bloat it dry using paper towel.
7.Using a sterile swab, swab the surface of the washed produce.
8.Slightly open the “After Washing” section of the plate and streak the agar plate.
9.Keep the plates in incubator at 37◦C for 24 hours.
10.During the next lab meeting, count the colonies. If it is more than 100 colonies, write TNTC (Too numerous to count) in the report.
11.Write your observations in Lab report.
12.Once observation is completed, immediately put the plates in appropriate waste container for autoclaving.
Exercise 3: Food safety- Appropriate Storage of milk Materials:
Nutrient agar, sterile swab, marker, open container of milk, unopened container of milk
Method:
1.Obtain a nutrient agar plate.
2.Use a marker to divide the plate in half. Mark each half as “open container” and “unopened container”.
3.Slightly open the open container section of the plate, use a sterile swab, and dip it in the milk
that was in a container that was opened a few days ago. Dip the swab in the milk and gently streak the agar plate.
4.Repeat step 3 for milk that is in unopened container.
5.Keep the plates in incubator at 37◦C for 24 hours.
6.Count colonies. If it is more than 100 colonies, write TNTC (Too numerous to count) in the report.
7.Write your observations in Lab report.
8.Once observation is completed, immediately put the plates in appropriate waste container for autoclaving.
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