Growth and Enumeration of Escherichia coli

Formal Lab Report 1: Growth and Enumeration of Escherichia coli
Read “Writing Formal Laboratory Reports” in the lab manual and follow instructions.
Take a look at scientific publications to get an idea of “scientific language e.g.
http://aem.asm.org/content/74/22/6918.long
http://aem.asm.org/content/80/24/7659.long
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC291691/
You can use different search engines (e.g. NCBI PubMed http://www.ncbi.nlm.nih.gov/pubmed)
to look for suitable publications to be cited as references using appropriate keywords.

Additional instructions to be followed:
• Lab reports should be double spaced.
• Use font size 12 and 1” margins at the top, bottom, left and right.
• Do not exceed the recommended number of pages or words, where indicated! Note: TAs
will not mark pages exceeding the indicated page limits.
• Pages must be numbered (Page #1 is the page following the title page).
• Use at least two external references (e.g. your text book and a publication) in addition to the
lab manual.

Include the following:
Title page:
• Title
Abstract: maximum 250 words, briefly summarizing the objectives of the report, methods
used, and results generated. Example: http://www.ncbi.nlm.nih.gov/pubmed/7447444

Introduction (5 pages maximum):
• Overall goal
• Objectives for each experiment
• Brief background on:
o Growth of bacteria in a batch culture
o Importance of studying bacterial growth and enumeration
o Different methods of enumeration techniques
o Pour plate technique
o Membrane Filtration
o Most Probable Number Method
2
o Turbidimetric Estimation

Materials and Methods (3 pages maximum)
• Brief descriptions of the experimental procedures used, instead of explaining in great
detail the step by step procedure; simply refer to the lab manual.
• Note any changes made in the experiment.
• List the bacterial strains used in the experiment, writing the name out in full with the
abbreviated form in brackets if you wish to use the abbreviated for throughout the lab
report.
• Use scientific names correctly and pay attention to proper format.
• Materials and methods section should be written in past tense and in third person singular
(no personal pronouns “I” and “we”)

Results (no page limit):
• Where applicable, summarize your results in the form of Tables.
• Pay attention to proper legends for tables and figures!
• In general, headings for tables appear at the top of the table whereas figure headings
appear below the actual figure.
• Concise, but complete, description of the results obtained should be included in
paragraph form.
• Include data, sample calculations and 2 semilog graphs from the growth experiments
• Include observations of growth for each enumeration technique.
• Calculate the CFU/mL from each of the four enumeration techniques

Discussion (no page limit, but be brief and concise):
Discuss your results and do not forget to refer to tables included in the results section:
• Your results regarding the growth of E. coli in a batch culture at 37oC
• advantages and disadvantages (ie. limitations) of each enumeration technique
• Compare/contrast CFU/mL values, ie. Most/least accurate enumeration techniques
• Include any sources of errors
• Include answers to any questions in the lab manual in your discussion.
• Remember to cite the references

Conclusion:
Summarize final results/outcomes, relate to objectives.
References: Should be in numerical or alphabetical order, punctuation complete, and consistency
between references.