"Sighing Student TM" (a.k.a. truemonk at csulb.edu) asks an excellent pedagogical
question in his/her message "Entertotube II"
(message ID <Pine.NXT.3.91.950325053529.18093E-100000 at tern.csulb.edu>)
Namely, in his or her undergraduate microbiology lab, "why must we do all those
silly plates and tubes when we could use a single Enterotube II instead?"
As a professor who uses *both* individual plates/tubes *and* Enterotubes in a
general introductory (not mainly medical) microbiology lab, my answer would be
that oftentimes the old format works better. For instance, not all tests have
the same optimum temperatures and times of incubation -- having separate
cultures lets you treat them individually. Also, when the purpose is to detect
weak reactions or to let a novice (student) see *clearly* a result, the tubes
provide a much larger and more sensitive format for that. Finally, those tests
like V.P. and Indole which require the addition of a reagent to the medium can
be pretty messy in an Enterotube -- MUCH easier in a broth.
Enterotubes are wonderful -- as I said, I use them -- both because they expand
the range of tests we can do, and in order to show students how it's done "in
the real world". But there's also value in the silly tubes and plates.
Terry Hill
Rhodes College
Memphis Tennessee
