Theoretical Laboratory Project in Microbiology
Theoretical Laboratory Project in Microbiology (50 points)
The goal for this project is to design a well thought-out laboratory experiment that you can carry out in a lab or even at home. You will develop the hypothesis, the method (design) for the experiment; a plan on how you are going to collect the data, possible outcomes, and conclusions. In short, you are going to develop everything that one needs for an experiment without actually testing it.
Since this is likely to be one of your first experiences in designing experiments that are not simply “cook-book” exercises, I have compiled a list of suggestions and guidelines that should help you to carry out this project successfully. Please read the following guidelines carefully, and spend some time planning your experiment accordingly.
1. The more focused your investigation is, the more likely you are to be successful in devising clear-cut experiments. For example, if you focus your experiments on answering the question “Do bacteria survive longer on cutting boards made of wood as opposed to plastic?”, you should be able to devise simple experiments that can clearly answer this question “yes” or “no”. On the other hand, if you focus on a more general question such as “How do bacteria survive?”, you will have a more difficult time deciding what experiments to do and how to carry them out.
2. Realize that the time available for your research topic is limited to roughly 8 weeks of actual research time, and that you must sandwich this project into an already busy schedule. Choose a “bite-sized” project that is manageable within this time frame.
3. You may work in groups (no more than 4 if you choose).
Ideas for Research Projects
The following list is deliberately vague. I have suggested a number of possible projects, each of which can be varied considerably depending on your interests and ideas. This is by no means a definitive list; you may have other ideas for projects that do not appear here.
Quantitative Experiments. How many bacteria are in ________ (a kitchen sponge? a thoroughly washed hand? road sand? a gram of ground beef? etc.) This is one of the most straightforward, and yet surprisingly interesting, of experimental questions in microbiology. The basic procedures are simple: dilution series and viable count assays. One can modify these assays to even simpler, “semi-quantitative” assays for an initial screening.
Here are some possible applications:
* comparing the number of bacteria in a variety of water samples. This can be extended by looking for the presence of indicator organisms for fecal contamination: E. coli and Enterococcus faecalis .
* comparing the number of bacteria in eggs, meat, poultry, fish, or other foods. Samples are first weighed, then mixed with sufficient water to produce 1% solutions (1 gm/100 ml), and mixed thoroughly in a blender. Dilutions are assayed for total count. It is also possible to screen for the presence of certain pathogens (e.g. Salmonella) or fecal indicator organisms.
* comparing the survival of a pathogenic indicator organism (such as E. coli, an enteric bacterium that has similar survival abilities to pathogenic enterics such as Salmonella) on wood vs. plastic cutting boards. The FDA requires plastic cutting boards in food preparation, arguing that they are easier to clean. However, recent reports suggest that bacteria disappear from wood surfaces much faster.
* examining “microbiology in the home”. Where are bacteria found in greatest abundance? How contaminated is a sponge that is used several times a day to clean food?
* examining the variation of numbers of bacteria in different habitats. You can investigate the distribution of S. aureus on different parts of the same person.
* examining variation over time. For example, we know that bacterial numbers on hands goes down after hand washing. But how soon does it come back up, and to what extent? A careful study, in which the same skin area was swabbed at different times and then assayed for total count, might be very revealing.
? Write a 2 page, single spaced, typed, well-constructed (complete sentences, proper grammar / spelling) lab report of your experiment.(4 points)
o Creativity is encouraged.
? Include a reference section (as an additional page) with at least 4 citations including at least one published (journal or textbook) reference. (8 points)
o Use resources such as microbiology text books, encyclopedias, HCC Library databases (e.g. Pro Quest Biology, Pro Quest Nursing), journals, and online medical sites to research these questions. Indicate the source of information either in ACS or MLA format. Do not forget to include in-text citations every time you borrow someone?s idea, even if you paraphrased it. Be sure to include the publication date.
o Comment on the reliability of the source (why you think this source is reliable ? ?because it is on the internet? is NOT a good answer) under each reference.
o All references must be cited, and direct quotes from the references must be indicated as such, using quotation marks. However, in science writing, direct quotes are seldom used. Instead, paraphrase the information in the reference, and supply the citation.
? In the case of plagiarism, all students involved will receive a ?0? on this assignment. Thereafter, plagiarism will be handled according to the College?s Academic Honesty Policy.
? Please submit your assignment at the beginning of class on the 14th. Late submissions will result in pt deductions. 5 pts deduction for each day late. Rubric for each section is listed below.
You will be graded based on the following rubric:
5 3 0
Creativity of the idea for an experiment The idea is very creative and unique. The idea is interesting. The idea is not very creative.
Introduction Summarizes relevant background information from textbooks, articles, your lab manual, etc.
Includes what a student is going to do, why he/she is performing the lab, what he/she hopes to gain from the exercise
and how this will be accomplished. Some background information is summarized. Some important pieces of information are not included: what a student is going to do, why he/she is performing the lab, what he/she hopes to gain from the exercise
and how this will be accomplished. Background information is not included.
Hypothesis The purpose of the project is summarized in the hypothesis statement(s). The question(s) to
be answered is (are) clearly identified and stated using ?if?then?
statement(s). The purpose of the project is summarized but not as a hypothesis statement. No hypothesis.
Methods Clearly explains the design of the experiment. Procedures are listed in clear steps. Each step is numbered and is a complete sentence.
The design of the experiment is somewhat confusing. The design of the experiment is not though-out and/or impossible to perform.
Possible outcomes The possible outcomes are clearly stated and conclusion is made based on the possible outcome. The possible outcomes are clearly stated , but no conclusion is made. No possible outcomes and no conclusions are made.
Applications/Further questions Describes how the results answer the question (or not). Summary describes the skills
learned, the information learned and some future applications to real life situations as well as further questions that need to be answered. Describes how the results answer the question. But no further questions are asked. Does not describe how the results answer the questions.
Appearance/Organization Final report is typed and uses headings to visually organize the material.
All bolded rows in rubric are bolded heading in the report Final report is typed, but lacks organization. Not typed/submitted online
Spelling, Punctuation and
Grammar One or fewer errors in spelling, punctuation and grammar in the report. Scientific names
must be properly formatted. Three or four errors in spelling, punctuation and grammar in the report. More than 10 errors in spelling, punctuation and grammar in the report.
Works Cited Any information that is not student?s is cited. The quotation marks are used for direct quotes. In-text citations are used when information is paraphrased. Comments about the reliability of the sources are made. No in-text citations or reliability comments. No in-text citations or references.
Safety The project talks about safety and safety procedures. The design of the
experiment posed no safety threat to any individual.
The design of the
experiment may pose some safety threat to an individual.
No safety procedures are mentioned.