This document contains instructions for two microbiology practical experiments: 1) An experiment to demonstrate the importance of hand washing by culturing plates with fingers that have been washed for different time intervals and observing bacterial growth. 2) An experiment to determine the presence of microorganisms in oral liquid medicine by collecting a sample, culturing it on nutrient agar plates, incubating for 24 hours, and observing the plates for bacterial growth.

1. Microbiology Practical

2. Name of the experiment: Microbiological assessment of unwashed and
washed hand
• Introduction:
• According to available scientific data, since the mid of 18th century, hand washing
is considered essential before any standard medical procedure.[1] Hand washing is
so important that some religions have also emphasized it. For example, Prophet
Mohammad (Islamic Prophet) has said when human beings wake up every
morning; they should wash their mouth and nose for the purpose of elimination
primary infection of the noses (Jamea al Saghir Vol. 1, Page 69). However, based on
the current knowledge, the importance of the hand washing is reported to have
started about 200 years ago. Previous studies results showed the important role of
normal bacterial flora in human health and divided it into two groups: transient
and intransient and their benefits have been demonstrated.[2] Recently, the role
of health provided and importance of protective barrier of intransient bacterial
flora has discussed, and the research results showed the impossibility removing
them.[3] While the variety, removable and changeable of transient of bacterial
flora in medical personnel enhance transmission of pathogenic bacteria in the
hospital environment.
• However, hands washing as one of the effective measures adopted to prevent
infectious agents, including various pathogenic bacteria.

3. • Objective: The purpose of this lab is to demonstrate-
• the importance of hand washing.
• Importance of the amount of time spent washing hands
•
• Materials:
• Running tap water
• Hand soap
• Timer
• Procedures:
• Prepare nutrient agar media
• Pick one person to be the hand washer and one person to be the timekeeper.
• Both will have the opportunity to complete each of the experiments, so you will each be washing
your hands two times.
• For each trial of this experiment, the timekeeper (the partner not washing hands) will be
responsible for determining the cleanliness of the washer's hands at each time interval.
• Put fingers of one hand on each nutrient agar plate.
• Incubate for at37oC for 24 hours to observe bacterial growth.

4. Name of the experiment:
Microbiological analysis of oral liquid
• Objective:
• To determine the presence of microorganisms in oral liquid medicine
• Materials and Equipment:
• Sterile pipettes
• Nutrient agar
• Petri dishes
• Incubator
• Spreader
• Alcohol
• Bunsen burner
• Procedure:
• Sterilization
– Ensure all equipment is thoroughly sterilized to prevent contamination.
• Sample Collection
• Carefully collect ……. amount of the sample with help of micropipette
• Spread on the nutrient agar media
• Incubate at 37oC for 24 hours
• Observe the plate
• Result and discussion