Antiseptic Lab

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The Relation of
Antiseptics and
Bacteria Growth
Purpose: To explore the effectiveness of different levels of concentration of antiseptic and antibacterial products’ prevention of bacterial growth. Question: Amongst common household products, which antiseptic and level of concentration is more effective at inhibiting the growth of bacteria? Introduction:

Antiseptics are antimicrobial substances used on living tissue to reduce the possibility of infection, putrefaction or sepsis. The word “anti” is for against and the word “septic” is for infection. Antibacterial products are antiseptics that are proven to act against bacteria. Bacteria need a food supply, moisture, a certain temperature, a certain level of acidity and in most cases oxygen. To cut off these elements to a certain degree would prevent this growth of bacteria and that is what most antibacterial products do. Antiseptics are generally very different from antibiotics because they kill bacteria outside the body while antibiotics kill microorganisms internally. Antiseptics vary a great deal in their ability to prevent bacteria growth and destroy microorganisms, and there is also variation between the types of bacteria each antiseptic target. Certain antiseptics are also more specialized towards different areas that are either less delicate or more delicate such as the use of silver nitrate which does not kill as many germs as a stronger antiseptic, but can be used on delicate tissue. Furthermore, antiseptics vary in their speed, meaning the time required for different antiseptics to work, actually varies depending on the antiseptic. Some antiseptics are slow but some are very fast such as Iodine, which kills bacteria within 30 seconds. Scientists have created systems for measuring the action of an antiseptic through the comparison of bacteriostatic action and phenol (under the same conditions against the same microorganism), which was called the phenol coefficient. This system was directed towards medical surgeries for avoiding infection which was founded on asepsis, meaning the absence of pathogenic organisms.

Hypothesis: If Mr. Clean, an antibacterial product, was placed in a petri dish with bacteria, then it would be most effective in its highest concentration, and would be more effective in every level of concentration , at preventing bacterial growth in comparison to the other antibacterial products, due to the strength and diversity of its active chemical substances that work to prevent bacterial growth. Materials:

-4 petri dishes
-nutrient agar
-bacteria(from any moist nearby source)
-cotton swab
-masking tape
-dish detergent
-Mr. Clean dish soap
-12 paper punched “circular disks”
-12 beakers
1.Set up materials(refer to diagram, Figure 1)
2.Take a marker and divide each lid of all 4 petri dishes into four sections, numbering each section. Label each dish appropriately to differentiate between different antiseptics. 3.Take the cotton swab and swab bacteria from a surrounding source or a cultured dish of bacteria. 4.Inoculate each Petri dish equally, covering the entire dish in horizontal motions, and then vertical motions, gently rubbing the swab across the surface of the nutrient agar. 5.Take a pair of tweezers and dip one paper punch into a pure concentration of mouthwash, (making sure not to drip on the dish), and place the paper punch in the middle of section one on the appropriate Petri dish. 6.Repeat step 6 using 1/10x of the mouthwash, and 1/20x of the mouthwash (by diluting it with water), leaving section 4 as a blank section for the control 7.Repeat step 5-6 with dish detergent, bleach, and Mr. Clean dish soap. 8. Close each lid and surround the edges of each dish and lid with masking tape 9.Store the dishes in a neutral environment and wait 48 hours. 10.Using a ruler, measure the inhibition ring around each paper disk, making four separate...
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