Good indicator for effect of temperature on respiration in yeast

The results using Methylene blue as the indicator for the A level AQA required practical No. 9 "An investigation of the effect of temperature on respiration in yeast" have always been poor. We have just had very successful results using 1% 2,3,5 triphenyl tetrazolium chloride (TTC) indicator in place of Methylene blue. It is CLEAPSS recipe no. 13. The indicator is colourless but turns red when reduced.
This is a good video link showing the prac using TTC.
Nice to have a really successful prac.


Best dressed trans' tech in the dept. X
Yes, we used Methylene blue for ages, but have now got TTC. Not sure that it made too much difference but it's nice to have a different colour to dangerous blue sometimes.