DLR 3: Cell Biology – Materials & Methods
Instructions
We Are All Responsible for Maintaining Academic Integrity
Read the Academic Integrity section of this Pressbook, including the resources we have provided.
While you are responsible for ensuring you do not commit academic dishonesty (e.g. plagiarism, inappropriate collaboration) according to any of the relevant offenses and explanations listed in McMaster’s Academic Integrity Policy (e.g. section 18 and Appendix 3), we have provided additional details regarding expectations for the LIFESCI 2L03 assessments. You are responsible for reading our expectations in regards to appropriate academic behavior (e.g. for group vs. individual work) and how to reference sources of information for individual assignments.
In order for your assignment to be graded, you must acknowledge on the assessment cover page that you have read the Academic Integrity section of this Pressbook and our expectations (see the links above). The cover page template provided to you contains this acknowledgement.
Refer to the ‘Materials and Methods‘ section of the lab report writing guide for details on on how to prepare this section
- This LRWG section, in addition to this assignment overview page, acts as the SPECIFICATIONS for what we are expecting for a submission to be graded with a pass
- Recall that DLRs are graded as pass/fail
- If you do not submit this assessment, it will be noted as 0 in the Avenue to Learn gradebook)
- A submission that does not meet the specifications will receive a fail (noted as a 1 in the Avenue to Learn gradebook)
- A submission that meets the specifications will receive a pass (noted as a 2 in the Avenue to Learn gradebook)
- A submission that exceeds the specifications will receive a pass (noted as a 3 in the Avenue to Learn gradebook)
- These numerical notations are not percentages, scores, or anything that can be used to mathematically calculate a new value. In fact, a 2 and a 3 are identical when we record your final letter grade at the end of the semester.
- You should refer back to the GradeGrid if you want a refresher of how DLR completion is used to determine your final letter grade in the course at the end of the semester
Write a summary of the materials you used, and the methods performed for the experiments in the Cell Biology lab you completed (passaging cells and counting with a haemocytometer). A Materials and Methods section provides an overview of the procedures that were performed when conducting experiments, and documents the scientific approaches used. This section could be separated with subtitles into different sections of distinct methods employed (e.g. animal care, tissue preparation etc.). Materials and Methods are written in paragraph form, with materials (and their product origins if this could play a role in being able to replicate an experiment accurately) provided in-text.
NOTE: Methods sections are different from protocols. A protocol is a step-by-step procedure in list format (like what you see in this Pressbook), while a methods section is a summary of the procedure and provides information on any changes made to established procedures.
The product origins for the materials used in lab today where the origin is relevant are provided below: (Note: A lot of the other materials don’t require their origins to be mentioned in a materials and methods section. You want to mention the origins if the specific product or vendor is going to impact the results in the experiment. It shouldn’t matter what brand your pipette type was, but it might matter what brand of cell culture media you used!)
- 1X Phosphate Buffered Saline (PBS) (BioShop, Burlington)
- Unsupplemented DMEM Cell Culture Media (Gibco, ThermoFisher Scientific, Mississauga)
- Supplemented (with 10% Fetal Bovine Serum, FBS) DMEM Cell Culture Media (Gibco, ThermoFisher Scientific, Mississauga)
- 0.1% Trypsin-EDTA enzyme (Gibco, ThermoFisher Scientific, Mississauga)
- Primostar 3 microscope (Zeiss, Germany)
- Axiocam 105 microscope camera (Zeiss, Germany)
- Axio Observer inverted fluorescent microscope (Zeiss, Germany)
- Zen software (Zeiss, Germany)
- C2C12 mouse myoblast cell line (Cedarlane, Burlington)
- 0.4% Trypan Blue Dye (Gibco, ThermoFisher Scientific, Missisauga)
The rest of the materials are mostly just consumables or are staples in every laboratory – you wouldn’t need to tell your reader “pipette 150 μl of cell suspension using a P200 pipette (Sartorius, Canada) with a P200 pipette tip (VWR, Canada)” because this would be common knowledge if the person reading the work already works in a laboratory, and they would probably have their own pipettes and pipette tips of similar brands. It would not make a difference to the volume of the amount if you used a pipette from Gibson, or a pipette tip from Fisherbrand, instead of the ones we had in the classroom this semester. You would be fine to just say “used 150 μl of cell suspension …” and this would be an appropriate level of detail for the target audience.
- 10 ml serological pipettes
- 1.5 ml microcentrifuge tubes
- 0.2 ml microcentrifuge tubes
- 60 mm tissue culture (TC) dishes
- P1000 pipette tips
- P20/200 pipette tips
- Tip Waste Container
- P1000 micropipette
- P200 micropipette
- P20 micropipette
- Permanent Marker
- Green Pipette Aid
- Aspirator Pump
- Biosafety Cabinet
- Tube racks (0.2 ml, 1.5 ml, 50 ml)
- Haemocytometer
- Coverslip
- 70% Ethanol
- Cell Counter
- Liquid Waste Container
- CO2 Incubator
- Mini-vortex
Must be 450 words or less. Anything written after the word limit will not be considered when assessing your answer.
- NOTE: Your DLR assignments MUST include the course cover page in order to be graded. Failure to include the cover page will result in a failed assignment. We require the cover page because it serves as an agreement that you comply with the course academic integrity policy.
