Lab Exercise PART 1
Lab II: Stem Cells: Replacement, Regeneration and Repair
Please read through the laboratory exercise and follow the directions. It is often helpful to look over the entire lab first before you begin.
You will be entering your answers to the lab questions in the separate laboratory report. When you complete your laboratory report, submit it in the lab report section of Laboratory Contents and Activities.
Part 1
Virtual laboratory: Experiments and the Scientific Method
For this laboratory session you will view this 58-minute video_(new window) of Dr. Melton of Harvard. In this video you will be introduced to his work on stem cells and its implication for the treatment of pancreatic disorders, specifically Type I diabetes. This video has remarkable clips that take you through the stages of development, the source of stem cells, and potential gene therapies. You will see some of the experiments that show the underpinnings of our knowledge of how the pancreas maintains its cells. Experiments with mice show you why bone marrow transplants can be successful.
Read through this lab before looking at the video. This will help you focus on the experiments for the Lab Report. Answer the following questions in your lab report and submit it in the Lab II Report section of Laboratory Content and Activities.
Lab Questions (Note: a separate answer sheet is required for submission. Download it from the Lab Report section, save it as a Rich text file – rtf, add your answers to the questions, save and submit it in the designated area).
Experiment 1: Hematopoietic stem cell experimen
t (39 min, 32 sec; #30)
1. In this part of the video, Dr. Melton describes an experiment with a mouse that has been irradiated to destroy its blood cells. For one part of the experiment, the irradiated mouse was given whole blood.
a. Generate a hypothesis for this experiment.
b. Generate a prediction for this experiment.
2. In another experiment, an irradiated mouse was given a single hematopoietic stem cell.
a. Generate a hypothesis for this experiment
b. Generate a prediction for this experiment.
c. Discuss why there is a difference in the outcomes of the two experiments.
Experiment 2: Genetic Pulse-Chase experiment (41 min, 47 sec; #32)
3. Dr. Melton discussed how this experiment led to conclusions about the replacement of pancreatic cells.
a. What is the reason for labeling the cells in this experiment?
b. Why do we know that these cells are fully differentiated?
4. Had this experiment showed that the maintenance of the pancreas was due to stem cells, what would the cells look like
a. in the Pulse slides at time 0
b. in the Chase slides at the end of the experimental period
5. In Type I diabetes, when the beta cells are destroyed by the immune system discuss what would be the likely outcome if we added stem cells to this individual’s pancreas.
Part 2
Discussion: Implications for Human Biology
Stem cell research is a complex and many faceted topic. Now that you have seen some of the research from Dr. Melton’s laboratory at Harvard and his colleagues it is important that you look at the scientific literature to see what is happening today.
Think about the following questions: