20.109 | Fall 2007 | Undergraduate

Laboratory Fundamentals in Biological Engineering


Module 2 Assignment: Expression Engineering Written Report

You are asked to write a formal lab report detailing your work in this module. Specifics for each section of this report are detailed below. Be sure to re-read the Guidelines for writing a lab report.


  • Please keep the number of words under 250.
  • Do not include references in the abstract.
  • Try drafting this section after you’ve written the rest of the report.
  • If you’re truly stuck, start by modifying one crystallizing sentence from each of the sections of your report.
  • Please do not plagiarize (accidentally or other) the class wiki. This applies to your entire report.


The homework you wrote after the first day of this new module will serve at the heart of your introduction. You should add (at least) one final paragraph to narrow the information “funnel,” ending your introduction with a clear description of the problem you’re studying and the method you are using. If you would like to preview for the reader your key results and conclusions in the last sentence of your introduction, you may.

Materials and Methods

If you used any kits for any of the manipulations, it is sufficient to cite the manufacturer’s directions, e.g. “RNA was prepared with the Qiagen RNeasy kit” Subdivide this section into the following

  • DNA and RNA
    • siRNA design
    • psiCHECK2
  • Mouse embryonic cell culture and transfection
  • Luciferase assays
  • Mouse whole genome microarray
    • mention kits as relevant, including any deviation from published protocol if any
    • mention how much RNA was used
    • describe array analytical methods in results section rather than in Materials and Methods



You should include but are not limited to the following figures and tables

  • Table
    • include siRNA you designed, plus scrambled, and positive control sequences
  • Table or figure
    • luciferase data
  • Figure
    • images of your transfected cells
  • Figure
    • microarray analytics
  • Figure
    • microarray conclusions

Each figure should be numbered, and should have a title and legend

Results Text

  • In paragraph form, describe each figure and the observations you made.
  • As much as possible, reserve conclusions about your data for the discussion section.


You should include but are not limited to

  • Conclusions you can draw from your work, including any uncertainties
  • Other data (published or personal communications) that support or contradict your conclusions. For example, you’ll want to look at
    • The data collected by the other lab for your same siRNA
    • And also what your labmates found for their siRNA
  • Limitations of your work, e.g. what kinds of experiments/controls/samples would have been great to include
    • Luciferase activity from microarray data?
    • Off-target effects from microRNA activity?
  • Next experiments you would like to try to extend your findings and strengthen your conclusions


  • Carefully format these, including a wiki citation like: “20.109 F'07 lab wiki: URL accessed on January 1, 2020.”
  • Do not include encyclopedias (including Wikipedia) in your reference list since these sources are insufficiently scholarly. You should find the primary references that support those summaries.
Learning Resource Types
Lecture Notes
Presentation Assignments
Written Assignments with Examples