Question

Hand washing techniques lab questions. In this laboratory activity, we are using a product containing tiny particles that fluoresce or glow under ultraviolet (UV) light. The product is called Glo Germ™. These particles stick to your skin; however, they can be washed away just like actual microbes. You will apply Glo Germ™ to your hands and then wash them. Afterward, you will perform a series of steps that simulate common laboratory procedures in which contamination could occur. When you touch objects while you have Glo Germ™ on your hand, the particles transfer to the object you are handling. You can track Glo Germ™ “contamination” using a small UV light source. This investigation demonstrates how easily contamination can occur and shows the proper ways to eliminate possible contamination.

Questions for Lab 11 Summary:  

1. What is the name of the substance you are applying to your hands in this experiment?
2. Why is an ultraviolet light required in this experiment?
3. Where (beaker, lab apron/coat, pipette, tubes, rack, or work area) did you see the most “contamination spots” in this experiment, and why do you think that area got the most contamination?
4. How would this experiment’s results be different if you used 70% ethanol in the beaker instead of water?
5. Let’s say you added an additional treatment group where instead of washing your hands you applied a hand sanitizer during Step 2 – how would you expect the number of contaminated spots to look and why?

Answer 1

1) The name of the substance that is being applied to the hand is the Glo GermTM .

2) The Glo Germ product has tiny particles that are fluorescent is nature and hence can be visible by using the UV light which will make them glow.

3) We can see the most contamination spots in the work area itself. If it is seen most in the work area, it means that the area has been contaminated most times because it has been touched by the contaminated hand most of the times.

4) 70% ethanol can be a sterilizing agent. So, if the ethanol was used instead of water, the contamination could have been less. Even if the contamination did occur, ethanol would sterilize the glo germ and make the fluorescence particle inactive.

5) If hand sanitizer was used instead of the water during washing, the effect would have been same as the use of ethanol. Hand sanitizers do contain ethanol in them and hence make the contaminants inactive and hence less transmission.