Lab Report: Effect of Ultraviolet Radiation on DNA, Cell Viability, and Mutation Frequency
This report will be on exercise 39: Effect of Ultraviolet Radiation on DNA, Cell Viability, and Mutation Frequency
This report will follow the formatting of a standard scientific paper complete with include an introduction, methods, results, and discussions section with appropriate citations. You will need to cite the lab manual and a minimum of one peer reviewed sourcs (peer reviewed refers to scientific articles published in a scientific journal or a textbook if applicable. Non peer reviewed sources, such as blogs or Wikipedia will not be accepted). Instructions for writing a good lab report can be found in the :Writing Lab Reports for Prokaryotic Microbiology Lab.docx Below is a brief description of what should be mentioned in each section:
Introduction: start broad with background information and narrow down to the current experiment. You should address important questions such as what is UV radiation? How does it impact bacteria on a molecular level? What implications do these changes have on viability and mutation frequency? How to bacteria respond to UV damage? Are some bacteria better equipped for recovering from UV damage? These answers will provide the background necessary to understand the importance of this experiment. This is where your peer reviewed sources will likely be the most useful. The background should be followed with a short description of the experimental purpose and your hypothesis.
Methods: Describe the experimental procedure show in the lab video and discussed in the manual. Be sure to mention how the data was collected and analyzed. A good methods section converts a protocol to a paragraph format that gives enough information to replicate the experiment without including any extraneous details.
Results: this is where you describe what happened so be sure to discuss what the results look like in a short paragraph. Mention the type of growth seen and the number of colonies counted for each plate and each condition. You should present this data in both prose and a table. There is no need to include photos of plates since the table will show your data. Be sure to caption your table with enough information where someone can read the caption and understand the experiment and results even without reading the rest of the paper. Your caption should be referenced in the results paragraph. For example: your caption would describe what is in the table and then in the main body paragraph you might say that the number of colonies per plate for ____ exposure was ____(table 1).
Discussion: this is your chance to explain your results and link them back to the experimental question. You should start by restating your hypothesis and then discuss how your results relate to what you know about UV damage. It is important to mention if your results do/do not match with published results (here is a good place to integrate the sources from your intro). You should also mention if there were any possible problems/conflicts associated with this experiment. If everything went perfectly, you should mention a possible problem that might have been encountered in this experiment.
Citations: should be parenthetical in text and should be included at the end in a short citations/references section. We are not particular about citation formatting as most scientific journals have their own requirements. It is good practice to mirror your citation style off of the standard for the field (e.g. if you cite a paper from Nature Microbiology, you can adapt your citation style to match that of Nature Microbiology).
Remember that being clear and concise is an important concept in scientific writing.
Do include important details, for example: what types of media were used, what species were used, how long were they incubated for, how long were they exposed to UV light, how did you quantify growth, were there any quantifications in mutation rates, were there any statistics applied, etc…
Results: examples include: how many colonies were seen, sizes and colors of species, was there any contamination, etc.
Important: include a table using proper captioning. Convention is to include the label of the table (i.g. table 1 shows _____). In the table will have the species, and the number of colonies counted for each exposure time (see picture).
Be sure to dicusss the significance of the results. (I.e. if there were more colonies from species A than there were from Species B, how does this relate to real world expectations? does it support hypothesis? Is there anything off in the data? Any pitfalls in the data or in the technique used? )
