We have been using the potato disc respiration lab from Carol Reiss's
plant physiology lab manual for the last 4 or 5 years and it just
hasn't worked very well for us at all.
In brief, the protocol is to punch out two sets of small discs of
tuber tissue. One set is fresh and one is aged for 24 hr to induce
the alternative oxidase. Discs are then immersed in a redox-sensitve
dye in the presence or absence of KCN or an uncoupler. Expected
results are more cyanide-resistant respiration in the aged discs than
in the fresh and a higher rate of dye reduction in the presence of
We generally get extremely average results. Aging does very little
to any of the rates. KCN tends to reduce rates a little bit. The
uncoupler increases rate a little, sometimes.
Does anyone have experience with this exercise? I would love to find
out what we are doing wrong.
p.s. Or does anyone have Carol's email address? I can't find it anywhere.
Robert R. Wise
Dept. of Biology
800 Algoma Blvd
Oshkosh, WI 54901
(920) 424-3404 (tel)
(920) 424-1101 (fax)
Have a look at The Structure and Function of Plastids at