GROUP+1

How Effective Are They? Many people around the world, faces the problem having unsanitary hands, especially children who lacks the knowledge of how important it is to wash their hands. Germs, and bacteria are everywhere and can get into our hands easily; from touching a doorknob, the handheld of escalators, pets, chairs, toilets, mobile phone, and other objects. Many Binusians are not aware of the fact that it is unsanitary to sit on the floor, where there are many germs, where most of us rarely wash our hands, after sitting on the floor. Where these bacteria and germs could cause disease to enter our body. The most common, is a food-borne disease, where we eat with unsanitary hands, thus we will have a stomachache. It could also conduct a critical sickness such as typhus. This hygienic problem that most people face, is usually because of their laziness of finding water and soap. An alternative was found where hand sanitizer was introduced to the world in 1988. Therefore in this experiment, we would like to determine the most effective waterless hand sanitizer that could kill the most bacteria, thus preventing many from diseases. ** BIOLOGY ** Background research: Bacteria will grow in an agar, which is a suitable medium for the microorganisms, which is extracted from red algae (polysaccharide). As because bacteria are living things, it also needs food source, where if the agar is added nutrients the growth of bacteria can result more successfully. Aim: To determine the effect of different concentrations of ethanol in hand sanitizers with bacteria growth Hypothesis: The highest concentration of ethanol that is contained in the hand sanitizer, will have a greater clear zone, Variables: Controlled: amount of sanitizers in each petri dishes, time for bacteria to grow (24 hours) Independent: hand sanitizers used with different percentage of alcohol containing in them. (50%, 60%, 70%, 90%)   Dependent: the growth of bacteria in the clear zone Materials: Method: ** CHEMISTRY ** Background Research: The use of aloe Vera Aloe Vera contains saponin nutrient believed to kill the germs. Aloe Vera has some specific properties that work wonders on the skin by nourishing, moisturizing, providing collagen support, regenerating new cells, thus preventing wrinkles. The use of different concentrations of alcohol Both ethanol (ethyl alcohol) and isopropanol (isopropyl alcohol) are alcohols that kill bacteria. Alcohols kill bacteria by first making the lipids that are part of the outer protective cell membrane of each bacterium cell more soluble in water so that the cell membrane begins to lose its structural integrity and fall apart. As the cell membrane disintegrates, alcohol can then enter the cell and denature proteins within each bacterium. Highly concentrated amounts of alcohol (70% and higher) can kill bacteria by damaging the plasma membrane and denaturing proteins within the cell. It is recommended by PHAC that hand sanitizers should contain between 60 and 80 percent alcohol in order to be an effective product for cleaning your hands. Aim: To determine the best concentration of ethanol for hand sanitizers by observing the clear zone on the Petri dishes. Hypothesis: We think that 90% ethanol is the best percentage for hand sanitizers in order to kill the greatest amount of bacteria in an effective matter. Therefore, it has the widest clear zone amongst the different hand sanitizers. Variables: Controlled: Amount of ethanol (75 ml) and aloe Vera gel (25 ml) in each hand sanitizer, Amount of hand sanitizer in each Petri dish (2 drops) Independent: Different percentages of ethanol in hand sanitizers (50%, 60%, 70%, 90%) Dependent: Diameter of clear zone Materials: Procedure: ** CONCLUSION ** Based on the experiment that we have done. We observed that on the petri dishes that contain 50% of ethanol in the hand sanitizer, within 48 hours, the clear zone is visible. The diameter of the clear zone is 1 cm. However, inside the clear zone, we can see that there are a few bacteria grow in it. In the petri dish of bacteria that contain 60% of ethanol in the hand sanitizer, the clear zone is scattered around. the clear zone is not surrounding the spot that has hand sanitizer on it. In the petri dishes that contain 70% of ethanol in the hand sanitizer, the clear zone is not very clear. Inside the clear zone, there are also some bacteria grow in it. Lastly, in the petri dishes that contain 90% of ethanol in the hand sanitizer, the clear zone is very clear and there is no bacteria grow inside the clear zone. Hence, the higher the concentration of the ethanol, the more effective the hand sanitizer will be to kill the bacteria. ** EVALUATION ** When doing this experiment, we found several weaknesses from our experiment. First, some of the clear zone that are in the Petri dish full of bacteria are scattered around. This is because after we put two drops of hand sanitizer in the middle of the Petri dish, we need to heat the side of the Petri dish. Probably, when we did that, the hand sanitizer was moved around, therefore the clear zone was not in the middle surrounding the spot. Second, the bacteria are not controlled. It is not controlled because when we want to pour the nutrient agar into the Petri dish, some of the nutrient agar that has been measured was already freeze, therefore we need to reheat it and put in another bacteria in it. Lastly, the temperature might affect the bacteria growth since we did not put the Petri dish in the area that has an exact temperature, which is 37 degree Celsius. If it is below 20 degree or above 45 degree, it might affect the bacteria growth. This experiment also has some strength. First, the amount of nutrient agar in each Petri dish is the same. Second, after we knew that the nutrient agar was already freezing, we immediately reheat it. This can be the strength because if we leave it freeze, the result will be inaccurate. Third, after we put in the ingredients to make the nutrient agar, we wait until the color and the texture has changed. Lastly, after we pour the nutrient agar into the Petri dish, we waited until the nutrient agars freeze before we put in the hand sanitizer on the middle of it. In the next experiment, first, we will control the temperature. We will do that by putting the Petri dish in the incubator so the temperature will be controlled. Second, we will put the hand sanitizer exactly in the middle and we will make sure that when we heat the side of the Petri dish, it will not scattered around. Lastly, we will fasten the process when we pour the nutrient agar into the Petri dish so that it will not freeze and we do not need to reheat and put in the bacteria again. In that way, the amount of the bacteria will be the same.
 * Hand Sanitizers (Bernard, Gupita, Gwendoly, Jessica F, Jessica M, Mutia) **
 * 13 petri dishes
 * 500 ml of distilled water
 * 10 g of nutrient agar
 * autoclave (121˚ Celcius, 1.5 kPa)
 * 4 large beakers
 * 4 small beakers
 * 4 measuring cylinder
 * 4 pipettes
 * 4 spatula bucket scale
 * wrapping paper
 * pinset
 * millipipette
 * alcohol burner
 * lighter
 * paper for petri dish
 * cling wrap
 * heater
 * Scale
 * 1) 1. Sterilize Petri dish in autoclave 121˚ c 1.5 kPa
 * 2) 2. Cover the 13 Petri dishes with brown wrapping paper
 * 3) 3. Measure the required amount of nutrient agar with the scale. (10 g)
 * 4) 4. Measure distilled water 500 mL
 * 5) 5. Combine them together
 * 6) 6. Place them on the heater, and put the magnet to mix the substances, and wait until the nutrient agar is diluted, and change color
 * 7) 7. Cool the agar substance by placing it in the water bath.
 * 8) 8. when moderately cool, dip unsanitary hands in agar substance
 * 9) 9. pour 38 mL of agar substance in each petri dish
 * 10) 10. Cool agar substance on the petri dishes
 * 11) 11. Dip sterilized pinset into ethanol and burn it, use it to take the paper dish and place it on each petri dish
 * 12) 12. With the millipipette put 2 drops of each different hand sanitizer.
 * o One hand sanitizer; 3 petri dishes
 * 1) 13. Burn the sides of the petri dish, to eliminate excess bacteria surround, and seal 3 each petri dish with the 'cling' wrap
 * 2) 14. Incubate the petri dish in a 37˚ c temperature, for 24 hours and let the bacteria grow.
 * o check every 6 hours about the growth of the bacteria, and the diameter of the clear zone.
 * 75 ml of 50% ethanol
 * 75 ml of 60% ethanol
 * 75 ml of 70% ethanol
 * 75 ml of 90% ethanol
 * 100 ml of aloe Vera gel
 * 4 measuring cylinders
 * 4 large beakers
 * 4 small beakers
 * 4 pipettes
 * 4 spatulas
 * Aluminum wrap
 * 1) 1. Measure the required amount of each percentage of ethanol (50%, 60%,70% and 90%), which is 75 ml
 * 2) 2. Measure the amount of aloe Vera gel required (100g in each beaker)
 * 3) 3. Mix the ingredients with spatula