Dilution Factor 10,000 100,000 1,000,000 10,000,000 Plate colony count INTC* 613 120 18

Create a graph of this spectrophotometric data (using Excel or the graph paper below), labeling the four stages of the growth curve- lag, log (exponential), stationary, death. Be sure to label your axes properly and give your graph a title Time Culture Sampled                        % Absorbance 0 min                                                       5% 30min                                                              7% 60min                                                              9% 90min                                                              15% 120min                                                            25% 150min                                                            37% 180min                                                            49% 210min                                                            50% 240min                                                            49% 270min…

Why is it important to limit the quantity of cells used to prepare a smear?  Mark all that apply: 1. So that cells are not clumped and don't entrap stain creating erroneous results  2. So that the cells are spread out enough that cell morphology can be discerned 3. So that there are small groups of cells clumped together to make them visible 4. So that no contaminants are introduced onto the slide by being entrapped in clumps 5. So that the cells are spread out enough that the arrangement can be observed

Ten grams of hamburger were added to 90 mL of sterile buffer. This was mixed well in a blender. One-tenth of amL of this slurry was added to 9.9 mL of sterile buffer. After thorough mixing, this suspension was further dilutedby successive 1/100 and 1/10 dilutions. One-tenth of a mL of this final solution was plated onto Plate Count agar.After incubation 145 colonies were present. How many colony-forming units were present in the total 10 gramsample of hamburger?