Cell Biology Lab Homework 1

BIOS 312 Cell Biology Laboratory Homework 1 20 points Yusuf Suliman Name: ________________________________________________________________________ TA: Manasvi Vig ____________________ O FALL SPRING SUMMER 2024 YEAR: ___________ Complete the following assignment related to Keeping a Laboratory Notebook and Micropipetting and Preparing Solutions. Homework must be submitted using the link provided in your Blackboard weekly folder before 11:59 pm on Friday of the week it is due. Upload your completed assignment as a PDF, DOC, or DOCX file. Do NOT submit a JPG image of your homework! This will not be accepted, and you will not receive any credit. Your assignment will be checked with the plagiarism detection software SafeAssign to verify that you did not copy the work of another current or past student in the course. Feel free to attach extra pages if you need more space. 1. (4 points) You use a P-20 micropipette to transfer 40 µL of water to a microcentrifuge tube. Next, you use a P-200 to add 160 µL of dye to the same tube. Finally, you use a P-1000 set to 200 µL to remove the mixture from the tube. You see that there is a small amount of liquid remaining behind, however. Propose TWO specific and logical hypotheses to explain this and describe how you could test each one. “Specific” means something more than “I must have made a mistake ”and “logical” means that the hypothesis you propose could reasonably be expected to produce the observed outcome [2 pts for each hypothesis and explanation.] 1. You can not use p-20 to transfer 40µL 2. Dye and water were not mixed correctly Page 1 of 4 BIOS 312 Cell Biology Laboratory Homework 1 20 points 2. 3. (6 points) What volumes are the micropipettes shown above set to deliver? You must include the proper units to receive full credit. A. (P-1000): 520 UL [2 pts] B. (P-200): 21 UL [2 pts] C. (P-20): 20 UL [2 pts] (4 points) Convert each of these concentrations to the indicated units. You must show your work, with appropriate units, to receive full credit. In the first problem, for example, be sure to include a conversion factor that indicates the relationship between molar (M) and millimolar (mM) concentrations. You’ll get no credit for the work shown if units are omitted. A. 1.4 M = B. 35 M = 1400 0.035 C. 18 mM = 0.018 D. 0.2 M = 2 £ 105 mM [1 pt] mM [1 pt] M [1 pt] M [1 pt] 1:4M £ 1000mM = 1400 35¹n ¥ 1 £ 106mM £ 1000 = 0.035 18mM ¥ 1000M = 0:018M 0:2M £ 1 £ 106M m = 2 £ 105 Page 2 of 4 BIOS 312 Cell Biology Laboratory Homework 1 20 points 4. (6 points) You are a Clinical Scientist at Abbott Labs, working on the High-Sensitive Cardiac Troponin I test (hs-cTnI). Troponin I is a muscle protein found in the heart. When muscle cells rupture during a heart attack, they release troponin into the bloodstream. The greater the amount of troponin released, the greater the damage to the heart muscle. When patients experience chest pain or a suspected heart attack, a test is ordered at the hospital to measure the level of troponin in their blood. The currently approved tests have a limitation, however: they cannot reliably detect levels of troponin below 100 ng/L.* This is a problem because the tests can miss mild heart attacks, particularly in women since they exhibit lower levels of serum troponin than men, both pre- and post-heart-attack. You hope that the new assay will be more sensitive than existing troponin tests. Today you tested 4 sets of 100 blood samples with the new hs-cTnI method: 1) female patients after a confirmed heart attack, 2) female patients who had not experienced a heart attack, 3) male patients after a confirmed heart attack, and 4) male patients with no heart attack. The average levels of troponin detected in the samples by the hs-cTnI test are shown below: Sample type Female, after heart-attack Female, normal Male, after heart-attack Male, normal Average serum troponin level (ng/L) 8,920 89 63,451 568 *A nanogram (ng) is 1 billionth (10-9 ) of a gram. A. What was the purpose of this experiment as you would have written it in your lab notebook? The Purpose section should explain why you are doing the experiment or what its goals are. Remember that: 1. you are testing an experimental assay, not a method that’s already been FDA-approved for diagnosing patients, 2. you already know that women exhibit lower serum troponin levels than men both pre- and post-heart-attack, and 3. you already know the status of the patients who provided the blood samples. [3 pts] Question continues on following page. Page 3 of 4 BIOS 312 Cell Biology Laboratory Homework 1 20 points B. After studying the data in the table, write a Conclusion for the experiment as you would have written it in your lab notebook. The Conclusion should interpret the results (indicate what the data mean) and not just restate them. Was the Purpose/Objective of the experiment achieved? How do you know this? You should refer to specific results that support your conclusion. [3 pts] A. The purpose of this experiment was to evaluate the sensitivity of the new hs-cTnI assay in detecting troponin levels, especially focusing on its ability to detect lower levels below 100 ng/L. The goal was to assess its performance in di erent scenarios, considering the known gender di erences in troponin levels pre- and post-heart attack. B. Based on the data, the experiment achieved its purpose. The hs-cTnI test successfully detected signi cantly lower troponin levels in both male and female patients, including levels below the 100 ng/ L limitation of existing tests. This suggests the assay's potential to improve the detection of mild heart attacks, addressing a limitation observed in current diagnostic methods. The results support the conclusion that the new assay is more sensitive in assessing troponin levels. Page 4 of 4