From: Derek Gatherer (
Date: Fri 02 Dec 2005 - 12:06:14 GMT

  • Next message: Derek Gatherer: "test"

    Apologies if this duplicates in your inbox. The previous version didn't reach me, and some formatting problems have started to appear in some messages.

    Message was:

    Exactly, the selection medium simply gets living cells dumped in on top of the dead ones. The same flask is used, not a clean one. In the unselected medium there is passage (which means spinning down cells, taking an aliquot and seeding it into a clean flask with fresh medium). So tell me then, where's the control? What is being compared with what?

    At 20:46 30/11/2005, Dace wrote:
    >Derek,> From: Derek Gatherer
    <<>>>> Before you
    >start fulminating, Ted, I suggest you re-read Hill's>
    >paper. (bottom of p212 and the first paragraph of 213). Then
    >reread> his reply.I don't see the contradiction. In response to
    >your question, Dr. Hill saidthat at each passage the culture was
    >divided into two subpopulations whichwere both placed in clean
    >flasks. Here's what he wrote in his paper:"Briefly, cells in the
    >logarithmic phase of growth are, at each passage,divided into two
    >unequal samples and subcultured by seeding the large sampleinto a
    >selection medium and by growing the small one in a parallel
    >culturewithout selection."No contradiction there. Perhaps you were
    >thinking of what he wrote next:"The cell monolayer in the selection
    >medium, when depleted, is periodicallyreplenished by the addition of
    >fresh cells from the parallel culture."This is a separate issue,
    >having nothing to do with splitting the culture ateach
    >passage. Since the exposed culture is depleted by the toxin, it has
    >tobe replenished with cells from the unexposed culture. Are you
    >suggestingthat this somehow contaminated the unexposed culture? You
    >have yet toexplain how Dr. Hill's results were compromised.ted> At

    =============================================================== This was distributed via the memetics list associated with the Journal of Memetics - Evolutionary Models of Information Transmission For information about the journal and the list (e.g. unsubscribing) see:

    This archive was generated by hypermail 2.1.5 : Fri 02 Dec 2005 - 12:25:03 GMT