Essay on Serial Dilutions - 616 Words

Serial Dilution Activity Many applications require the determination of microbial numbers. Those applications can be either clinical or in a research setting. Clinical applications include determination of antibiotic efficacy and as well as therapy. Research applications include determination of the effectiveness of antimicrobial chemicals, radiation, etc. The viable count is most common or standard method used to quantitate bacteria. With this method only microbes that are alive and able to reproduce can be counted. Since microbes grow into such large numbers it is extremely difficult to perform this without diluting the microbial culture first. A key concept here is the ability of microbes such as bacteria and fungi to form visible†¦show more content†¦I would take test tubes of different concentrations of the bacterial samples put one sample of each on a petri dish; diluting the large amount of bacteria to different concentrations. A dilution of 200 X 10^-6 = 2x 10^8 cfu/ml. You would go about finding this out by taking four other test tubes adding 1.0 ml of to one of the test tubes and shaking them. I would use a general wide series of dilutions ranging from 10^2 to 10^8. After shaking this test tube #1 with 10^8 dilution, you would take a pipet and transfer 1.0 ml aseptically to the next test tube of 10^6. Shake the test tube of 10^6 dilution and aseptically transfer 1.0 ml to the test tube of 10^4 dilutions. Shake the test tube of 10^4 dilution and aseptically transfer 1.0 ml to the test tube of 10^2 dilution with a pipet. Now shake the test tube of 10^8and take a new pipet transfer 1.0 ml to one petri dish and 0.1 ml to another petri dish. Do this same task to test tubes 10^6 and 10^4. I would then go about mixing a agar with the 10^8. I would do this to the remaining plates and allow the agar time to cool and harden. When the plates have hardened I would then go about counting the plates that have between 25-250 colonies. This how I would go about double checking the accuracy of the concentration of thisShow MoreRelatedEvaluation Of A Chemical Substance1561 Words   |  7 Pagesspectrophotometer. This device consists of a spectrometer that produces light of any color (wavelength), and a photometer which measures the intensity of the light.2 In this experiment serial dilutions will be performed and from this, calibration curves will be produced. New solutions will be created from these dilutions and each new concentration will be found by using the concentration and volume formula given in the manual. In addition, Beer’s Law will be utilized to determine the concentrations ofRead MoreSpectrophotometer: Concentration and Standard Curve Essay805 Words   |  4 Pagesspectrum to determine the concentration of light absorbing molecules in a solution. (p.59) In this particular lab, our mission was to determine the protein concentration and the standard curve of the unknown sample of BSA. This, by preparing five dilutions of the unknown solution of BSA together with other known concentrations, and then experimenting by observing how the concentrations were passed through the spectrophotometer. The outcome resolved in the absorption levels being decreased, and thisRead MoreEssay about Micro Lab Project757 Words   |  4 PagesProfessor Rotibi ABSTRACT: Accurate evaluation of bacterial colonization as a predictive index for alfalfa sprouts has relied on a quantitative culture technique that provides exact colony counts per gram of tissue by culture of five serial dilutions of the alfalfa water. In this study 1 package of alfalfa sprouts were cultured by a semi-quantitative technique that enumerated the number of gram-negative enteric organism in 1 ml of alfalfa water. Exact colony counts from the experiment wereRead MoreBacterial Enumeration of Various Meat Products1161 Words   |  5 Pagescurrently collected samples of hamburger, suspension were transferred via serial dilution, and then transferred onto spread plates and pour plates. The samples were permitted to culture for approximately one week, and then enumerated through use of colony counting methods. Although, methods were taken to transfer each sample to their dilutions aseptically, any contamination may result in skewed results; however, the dilution number will directl y influence the number of bacterial colonies that formRead MoreThe Isolation Of Milk Whey904 Words   |  4 Pagesset of five serial dilutions of BSA and the purified samples were made as shown in Table * and *, respectively. Table 1. BSA standard serial dilutions. Cuvette Serial Additions 0.01% SDS Volume Dilution Factor 1 50  µL of 1 mg/mL BSA 950  µL 50  µg/mL 2 500  µL of #1 500  µL 25  µg/mL 3 500  µL of #2 500  µL 12.5  µg/mL 4 500  µL of #3 500  µL 6.25  µg/mL 5 500  µL of #4 500  µL 3.125  µg/mL 6 Discard 500  µL of #5 500  µL 0  µg/mL Table 2. Serial dilutions of purified ÃŽ ±-lactalbumin. Cuvette Serial Additions 0Read MoreLab Investigation : Cell Purple Dye Solution1042 Words   |  5 Pagesto the guiding question of: how to make 1 L of Pirate Purple dye. Section 2 Performing this lab, a serial dilution was set up for the red and blue dyes. After labeling 5 beakers A-D and a Stock of 30 mL of the dye solution, 10 mL of the Stock solution plus 10 mL of water was transferred into beaker A; then 10 mL of beaker A plus 10 mL of water into beaker B and so forth. After the serial dilutions of the red and blue dyes were taken, the molarity and absorbance for both dyes were calculated. UsingRead MoreQuestions On The Quantification Of Light Absorption And Transmittance As A Function Of A Solution1804 Words   |  8 Pagesthe procedure involved serial dilution. In other words, 50% of the original sample was transferred to container number two and diluted to the mark. This step was repeated with the rest of the containers; the idea was to reduce the concentration of each container by a factor of  ½. The unknown was dissolved as instructed in the label and the absorbances of four trials were obtained, to account for a 95% certainty on the concentrations reported. Sample of serial dilutions in Figure 2. (VolumesRead MoreAntibacterial Effects Of The Chloramphenicol Antibiotic On Escherichia Coli1473 Words   |  6 Pagesrange of 25ÃŽ ¼g/mL and 170ÃŽ ¼g/mL. Methods and Materials Our study took place in a laboratory in Duncan Hall at San Jose State University. The chemistry department of San Jose State University supplied our materials. We conducted serial dilutions and calculated our dilution factors using the equation: C1V1=C2V2 The study resulted in a series of agar plates containing E. coli and Chloramphenicol. The plates had progressively higher antibiotic concentrations (from no antibiotic on one end and excessRead MoreGrowth Curve Report1680 Words   |  7 Pagesgrowth of yeast is measured by using spectrophotometer and hemocytometer.We learnt how specthophotometer and hemocytometer use and also we learnt qualifications of hemocytometer and spectrophotometer.Serial dilution was used for this experiment and it was very important.Because of the serial dilution,we measured the number of yeast cells. The graph of growth curve was drawn and bacterial life cycle was understood with the graph.The purpose of the experiment was to calculate and draw bacterial growthRead MoreEssay Quantitave Plating642 Words   |  3 Pagessee the effects of pasteurization while emphasizing the process for serial dilutions. PROCEDURE See references (1) RESULTS As the dilution factor increased for both the raw milk (unpasteurized) and pasteurized milk samples, the number of colonies decreased. The number of cells/mL in the pasteurized milk sample is considerably less than the number of cells/mL in the raw milk sample. RAW (UNPASTEURIZED) SAMPLE Dilution Factor | Number of Colonies | Number of cells/mL | 10-3 | TMTC |