In reply to koalapie:
So you mean repeated measures of say the same animal, the same time..
So taking 100 blood tests on the same batch of blood and looking at the variability?
That was always the first step invalidating any new assay.. I'd generally look at 90-95% as being acceptable but again it depended on the magnitude of the change I was likely to be measuring...
My pHD was very industrial so it was about making quite cheap assays of stress which we could use in the field/industrial setting.. so if I could do x% more tests with an 80% accuracy in a given time it was preferable to another test which may have been 99% accurate which could only be done later on.
For me lactic acid would rise 10-20 fold in stressed animals, unstressed were 0-0.5 mmol.. so I'd use blood sticks sometimes which were much less reliable and more variable but would give me an idea to classify animals to unstressed or stressed. For them I think I accepted around 75% accuracy.. it was much less reliable than a blood test but was fit for purpose.