phage practice problems

DILUTION COLONY COUNT CFU/mL 1:106 155000   1:107 15500   1:108 1550   1:109 155   Given these values how would I fill in the rest of this serial dilution table? Also, what would be a 1:1 CFU/mL value based on this table?

Time point (min) Absorbance of culture at 660nm Approximate cell concentration Approximate # cells in 1mL extract 0 0.298 1.49 x 108 cells/mL 1.49 x 108 cells 10 0.316 1.58 x 108 cells/mL 1.58 x 108 cells 20 0.374 1.87 x 108 cells/mL 1.87 x 108 cells 30 0.429 2.145 x 108 cells/mL 2.145 x 108 cells 40 0.512 2.56 x 108 cells/mL 2.56 x 108 cells 50 0.544 2.72 x 108 cells/mL 2.72 x 108 cells 60 0.607 3.035 x 108 cells/mL 3.035 x 108 cells a. Using these data, prepare a growth curve of this strain ofEscherichia coli (E. coli).b. Estimate the doubling time for this strain of E. Coli. Clearly showhow you estimated this value from the empirical data presented.

Confluence cells added onto 100-wells plate, 2 ml trypsin added onto cells and 6 ml media added to dilute trypsin, 1 ml was used for counting, and average number of Cells counted was 24(DF 2) find out the the number of cells/ml and total number of cells in 7 ml? How many cells you need for 100 wells, assuming Number of cells/well is 10 to the power 4 cells?

A. A Aa A 三,三,行,E AaBbCcDdE Aa AaBbCcDdF AaBbCcDdF AaBbCcDd A Normal No Spacing Heading 1 Heading 2 =y updates, fixes, and improvements, choose Check for Updates. 1. You have found a putative virus which is able to infect a bacterium causing increased mortality and resistance to all antibacterial agents. You have systematically purified the sample but have an unknown concentration of viruses. You perform the following serial dilutions. 0.5ml 1ml 5ml 0.1ml 2.5ml 1ml 15ml 1 3 6 7 Phage Buffer 100.5ml 9ml 14.5ml 99.9ml 25ml 5ml 985ml Tube Dilution in each Test Tube (Show Tube Dilution in each Test Tube (Show your your work) # # work) 4 1 6. O Focus glish (United States) W 30 DII DD 000 000 F4 80 F7 F8 F9 F10 F3 F5 F6 $4 & 4 5 6 8.

and the minimum exposure time 1. Determine the minimum inhibitory concentration given the following data: Concentration of ethanol Number of colonies of E. coli on Nutrient Agar plates Exposure time (in minutes) 10 5 15 Distilled water +++ +++ +++ 40% +++ ++ + 70% 95% Minimum inhibitory concentration: Minimum exposure time:

Helping tags: Biology, bacteria, lag phase WILL UPVOTE, just pls help me answer the following questions and explain them clearly. Thank you. TOPIC: Bacterial Growth Curve 1. How may the following growth and culture conditions affect the length of the lag phase? EXPLAIN YOUR ANSWERS. a) inoculum is from an old culture b) shifting cells from rich culture medium to a poorer one c) exponentially growing culture is transferred into the same medium under the same growth conditions

Average plaques for bacteriophage A，B，C are 137，36，25. PFU/ml is average plaques multiply by the volume dilution multiply by the dilution factor. Show your working for each bacteriophage.

Biomedical Engincering Dept. Biocompatibility Hello sir, I know it takes precious Lab. Sheet-Level time. Please, I have a report on this Semester 1 subject. Only 5 papers within a Experiment Title: Cytotoxicity Test discussion solution. I want to solve the text of the keyboard. Thank you, Experiment no. 2 sir 1 12:34 PMA Objectives: Study the eytotoxicity and how it is measured. 1- Background Cytotoxicity can lead healthy living cells to three potential cellular fates. 1. Necrosis (accidental cell death): Rapid loss of membrane integrity and cell lysis 2. Apoptosis (programmed cell death): slower, more orderly, and genetically controlled 3. Cytostasis (a decrease in cell viability): cells remain alive but fail to actively grow and divide Importance of measuring cytotoxicity two major reasons 1. Either you want specific cells to die and look for an adequate compound/condition (cancer and immunotherapy) 2. Or you want to exclude cytoloxicity in specific cells (chemicals and drugs)…

Case Study: You are asked to inoculate lactose media (broth) with E. coli that was growing exponentially in glucose media (broth). You monitor the growth of these cells in the lactose broth using a viable plate count technique and plot the Growth Curve for E. coli growing c lactose. After a day of monitoring the cells, you note that the culture entered into lag phase growth initially and is now currently growing exponentially. In addition, you find that the cultures doubling time is 30 minutes. You know that the doubling time of E. coli in glucose media is 20 minutes. You did not change the oxygen content or temperature at Which you were growing the cells, E. coli is still aerobically respiring at 37°C. Question: If the lac operon is 'on' what does this imply about the cell? O The cell is dying and the lac operon is going to induce apoptosis. Apoptosis is truly cell death and the cells will enter into the death phase of the Growth Curve. O Lactose is being catabolized and glucose is no…

Vivid outline and Standard operating procedure of Viral hemagglutination inhibition test.

Apple puree was analyzed for petulin by HPLC-MS-MS after SPE clean-up.  The procedure was 10.0g of puree + 10μl of a 10μg/ml solution of isotopically labeled petulin as internal standard were treated with 10.0ml of pectinase and acetic acid, centrifuged, and filtered.  Four ml of the filtrate was passed through a SPE cartridge.  The petulin was eluted with 2.0ml of ethyl acetate.  The sample was evaporated to dryness and the residue dissolved in 1.0ml of the mobile phase. The analyte signal was 127 and the internal standard 197.  Calculate the concentration of petulin in the sample in μg/g (RRF=1).

Case Study: You are asked to inoculate lactose media (broth) with E. coli that was growing exponentially in glucose media (broth). You monitor the growth of these cells in the lactose broth using a viable plate count technique and plot the Growth Curve for E. coli growing on lactose. After a day of monitoring the cells, you note that the culture entered into lag phase growth initially and is now currently growing exponentially. In addition, you find that the cultures doubling time is 30 minutes. You know that the doubling time of E. coli in glucose media is 20 minutes. You did not change the oxygen content or temperature at which you were growing the cells, E. coli is still aerobically respiring at 37°C. Question: If you want to grow E. coli as quick as possible would you grow it on lactose or glucose? O Mixing the two carbon sources would provide the most optimal growth conditions. O Lactose because of the generation time being faster. O Lactose and an anaerobic environment. O Glucose…

Case Study: You are asked to inoculate lactose media (broth) with E. coli that was growing exponentially in glucose media (broth). You monitor the growth of these cells in the lactose broth using a viable plate count technique and plot the Growth Curve for E. coli growing on lactose. After a day of monitoring the cells, you note that the culture entered into lag phase growth initially and is now currently growing exponentially. In addition, you find that the cultures doubling time is 30 minutes. You know that the doubling time of E. coli in glucose media is 20 minutes. You did not change the oxygen content or temperature at which you were growing the cells, E. coli is still aerobically respiring at 37°C. Question: In order to determine the doubling time of E. coli a viable plate countris performed. This means that you are truly counting O Dead cells only via a microscopic count O Live cells only via membrane filtration or serial dilution O All cells via membrane filtration or serial…

a. Explain whether or not any of the methods in fi gure 2.9 could beused to determine the total number of cells present in a patient’s specimen.b. After performing the streak plate method on a bacterial specimen, theculture was incubated for 48 hours at 37°C. Upon viewing the plate, therewas heavy growth (with no isolated colonies) in the fi rst quadrant, but nogrowth was apparent in the remaining quadrants. Please discuss errors in the procedure that could have produced this result.

6 2 4 3 5 LABORATORY REPORT FORM EXERCISE 25 ASSAY OF ANTIMICROBIAL AGENTS: DISK-DIFFUSION METHODS What is the purpose of this exercise? Evaluate 1. For each of the disinfectants or antiseptics tested, determine the active ingredient. What class of inhibitory agent does it belong to and what is its mode of action? CHEMICAL AGENT Lysol Sanitizer Foaming Handwash Detergent. Desinfecting Hand Sanitizer ACTIVE INGREDIENT(S) Alhyl Dinethylaenzy/a. chloroxylenol 0.3% Alkyl, Dimethyl benzyl ammonium chlorides ethy benzyl A. C. Ethyl Alcohol 70% 1/Cleansing s Pray Hydrogen Peroxide Benzalkonium Lidocaine HC) An Septic CLASS OF AGENT MODE OF ACTION

ISOLATE #2 Results for "Isolate #2": ***Please fill out the table**** 1. Blood agar: 2. Nitrate Test: Test Results Interpretation Blood agar (type of hemolysis) Nitrate test 3. Gelatinase Activity: Gelatinase activity Resistant or Susceptible? Novobiocin Resistance Zone Diameter: 4. Novobiocin Resistance: 5. Coagulase Test: Coagulase (Sure-vue test) 2. Based on your results, what is the possible identification (Genus and species) of "Isolate #2"? nhes

Think about minimal inhibitory concentration (MIC) assays.  A set of tubes, all containing the same amount of bacterial cells, have decreasing amount of antibiotic X added to them.  Tube 1 had 0mg/ml, Tube 2 has 100mg/ml, tube 3 has 50mg/ml, 4=25, 5=12.5, 6=6.25, and tube 7 has 3.125.  If bacteria grew in tubes 1, 4, 5, 6, 7, what is the MIC of this antibiotic for this bacteria? Select one: a.None of the Above b.3.125 mg/ml c.25 mg/ml d.0 mg/ml e.50 mg/ml

for E-coli- Describe results for Gram reaction, cell shape and arrangement (look up information) What color changes were observed for each test? Any zones of inhibition (for antibiotics only)?

Please answer fast Dilution Problem. A culture of Staphylococcus is diluted as follows: (1) 20mL are added to 80mL of water. (2) 10uL from (1) are then added to 9.99mL of water. (3) A 10-2 dilution is made from tube # (2). (4) 100uL from (3) are plated for a pour plate and incubated.   Growth Problem.A culture with approximately 2x103 cells/mL were incubated. After 3 hours, the number of cells had increased to 3x105. a) How long was the generation time in minutes?b) How many generations have occurred

Q.6. You have a bacterial culture. From this culture suspension, six serial dilutions are made, and 1 ml is plated onto Plate Agar from the last dilution. After incubation, X colonies are counted on the plate. Calculate CFU/mL of the original Sample? (X=9)

Plaque assay (Bacteriophage Titer) Answer questions 2 & 3 2. Why don't bacteriophages continue spreading over the entire plate until all of the E. coli cells on the plate are lysed?  3. Why is it important that bacterial cells should be in the exponential growth phase for this experiment?

Match the methods discussed to the description of what it would be used for.                                                                                                         HPLC-UV                                                                                                         Visual range standard curve                                                                                                         Affinity chomatography                                                                                                         UV analysis of protein fractions                                                                                                         Gel filtration                                                                                                         Ion Exchange                                                                                                         SDSPAGE…

Diagram illustrating Miles & Misra technique for determining viable counts: 10ul 10-5 106 104 10-7 3. Set up controls of the donor and recipient cultures as follows: • Spread plate 0.1 ml of the donor culture over the surface of each of the 3 different selective media (i.e. nutrient agar + Ap; nutrient agar + Sm; nutrient agar + Rif) • Similarly spread plate 0.1 ml of the recipient culture over the surface of each of the 3 selective media • What is the purpose of this step?

IN YOUR OWN WORDS. Differentiate the following. (Not more than 10 sentences) 1. Aseptic Teachnique vs. Sterile Technique 2. Microbistatic Agent vs. Microbicidal Agent 3. Sterilization vs. Disinfection 4.How is radiation, autoclave and ultrasonic waves used in the hospitals or clinics as a means to inhibit the growthbof microbes? 5. How is filtration applied nowadays in relation to Covid-19?

d-6f06-490d-b3d3-cb18767c100 Post-Lab: Streak Plate Isolation Homework. Due in 12 hours 2/5 answered Unanswered Post-Lab: PIV 2.5 Homework Unanswered How do colonies of E. coli differ from those of P. mirabilis? inancwarnd

Z40 7 @ ۱۲:۶۲ لا يوجد SIM و السؤال Roller compactor and chilsonators are used in preparation of granules of aspirin. false true حفظ الإجابة

Give five (5) other examples of samples that are best prepared using Smear Preparation Technique (example: Human RBCs). Explain why.

INTERPRETATION OF RESULIS NEGATIVE: Two lines appear. One colored line should be in the control region (C), and another apparent colored or faded color line adjacent should be in the test region (T). This negative result indicates that the drug concentration is below the detectable level. POSITIVE: One colored line appears in the control region (C). No line appears in the test region (T). This positive result indicates that the drug concentration is above the detectable level. INVALID: Control line fails to appear. Insufficient specimen volume or incorrect procedural techniques are the most likely reasons for control line failure. Review the procedure and repeat the test using a new test panel. If the problem persists, discontinue using the lot immediately and contact your local distrībutor. READING OF RESULTS INTERPRETATION SONTROL TEST SAMPLE

A phagehunter performs a full plate titer using standard techniques (100 ul of each dilution added to 250 ul of Gordonia terrae cells) of a lysate obtained from an optimum webbed plate experiment. The phagehunter counts 72 plaques on the 10-7 dilution plate. Which of the following scenarios is the best choice for the phagehunter to do next? a.) The phagehunter has not achieved a high enough titer lysate to move forward with characterization experiments, so they should adopt a phage from direct isolation. b.) The phagehunter has not achieved a high enough titer lysate to move forward with characterization experiments, so they should go back to the pick-a-plaque experiment. c.) The phagehunter has achieved a high enough titer lysate to move forward with characterization experiments. d.) The phagehunter has not achieved a high enough titer lysate to move forward with characterization experiments, so they should try to make more optimum webbed plates.

An adult male patient (52 yr, 75kg) whose serum creatinine is 2.4mg% is to be given gentamicin sulfate for a confirmed gram-negative infection. The usual dose of gentamicin in adult patients with normal renal function is 1 mg/kg every 8 hrs by multiple IV bolus injections. Gentamicin sulfate (Garamycin®) is available in 2-mL vials containing 40 mg gentamicin sulfate per mL. Calculate: a. The creatinine clearance in this patient by the Cockcroft and Gault method and b. The appropriate dosage regimen of gentamicin sulfate for this patient in mg and mL.

Please answer fast 1. a. Give an example of lysogenic conversion. b. An example of lytic phage and temperature phage in E. coli.

Case Study #6: A 20 year old male college student develops a fever after gall bladder surgery and has a pus exudate around the incision. You receive a cotton swab of the exudate which you streak on a blood agar plate. Bacterial colonies on the plate show B hemolysis, and microscopic examination reveals Gram + cocci occurring singly, in pairs, and in short chains. Further testing reveals that the isolate is catalase negative and phenol red fermentation broth with mannitol turns yellow. 1. What is the name of the most likely bacterium causing this infection? 2. What is the most likely place that this bacterium originated to cause this infection?

LABORATORY REPORT: Aseptic Technique & Inoculation of Bacteria Guide Questions. 1. Why is direct flaming preferred when disinfecting loops and needles? 2. Why is it important to flame the entirety of the loop and not just the tip? What consequences can be seen when this process is not done correctly? 3. What is the difference between quadrant streak method A from method B? 4. Why do we use a pencil instead of a pen when labelling culture tubes or plates? Are there other alternatives in labelling? 5. Why is an inoculating needle used in Subculturing Techniques? Can a loop be used instead? NOTE: Please try to answer all of the question asked, i promised to give you a good ratings

a. What is the total dilution of Tube #4? Express the answer in exponential format. b. You plated 1 mL of the Tube #4, After incubating, you counted 500 colonies on the plate. What is the concentration of Tube #0? include units. c. How could you change the experiment in part B to get a plate in the countable range? Be specific about any dilution factors and/or plated volumes you would change.

Lung Cancer Patient   Whats the use of the given medications below: ● Cisplatin100 mg/m2 IV q4 weeks● Trametinib Dimethyl Sulfoxide 2mg/tab 1 tablet OD● Roflumilast 500 mcg PO● Spiriva Respimat: 5 mcg (2 actuations; 2.5 mcg/actuation)● Budesonide 1 neb q6hr● Hydrochlorothiazide 25 mg tab PO OD● Levothyroxine 175 mcg PO OD● Hydralazine 50 mg tab PO TID● Metformin 500 mg tab PO BID

Escherichia coli Mycobacterium phlei Bacillus Micrococcus subtilis luteus A B Figure 1: Agar Slant Cultures of Bacteria (Gary E. Kaiser, Ph.D.- Professor of Microbiology) . Observe and describe the colour of the slant cultures (A-D) in fig 1. ( . Define the following terms: pure culture, sterile medium, inoculum, aseptic technique, and colony. What is the name of the cultures that you used . Where they gram negative or positive Define the following terms: psychrophile, mesophile, thermophile, and hyperthermophile.