Biology Forum Cell Biology Cell cycle

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    • #14620

      Hi, I’m stuck with this question in my assignment. Can anyone help me with this?!!!
      1. A student attempted to determine the length of each phase of the cell cycle in a civet cell line. The student counted the number of cells in a culture and found that the number doubled every 23 hr. BrdU, a DNA precursor that can be detected by immunofluorescence microscopy, was added to the culture medium for 15 minutes and, then, the cells were transferred to BrdU-free culture medium. Cells were fixed immediately after removing the BrdU and at 0.5 hour intervals. The samples were processed for immunofluorescence using anti-BrdU antibodies. The results were:

      i) 43 out of 164 cells fixed immediately after removal BrdU were stained by anti-BrdU.
      ii) 8.0 hr after labeling, 0 of 12 mitotic* cells stained with anti-BrdU; at 8.5 hr, 0 of 16 mitotic cells were stained; at 9.0 hr 2 of 16 mitotic cells were stained; at 9.5 hr 16 of 16 mitotic cells were stained.
      (mitotic cells are all cells in prophase, prometaphase, metaphase and anaphase)
      iii) The first BrdU positive cells in late telophase were seen at 10.5 hr after labeling.

      2A. Determine the length of G1, S, G2 and mitosis.

    • #103837

      This is a classic pulse chase experiment. At t=0 the marker is inserted and then you follow its fate over time.
      In this case you need to ask yourself in what stage does the BrdU get inserted in the cells. Then you will be able to determine from your data what is the longest time it takes from the cell to go from that stage to the next and the next.

      Good luck

    • #104161

      Maybe you can get more idea in this post.

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