An experimental assay is a method to obtain a measurement with a defined instrument on a sample or subsample. Multiple assay types may be applied on the same sample or subsample, if the measurement does not destroy it. For instance, the wet weight of a permeabilized muscle fibre preparation can be determined based on a specific laboratory protocol (gravimetric assay), maintaining the functional integrity of the sample, which then can be used in a respirometric assay, followed by a spectrophotometric assay for measurement of protein content. The experimental design determines which types of assays have to be applied for a complete experiment. Destructive assays, such as determination of protein content or dry weight, can be applied on a sample only after performing a respirometric assay, or on a separate subsample. The experimental variability is typically dominated by the assay with the lowest resolution or signal to noise ratio. The signal to noise ratio may be increased by increasing the number, n, of repetitions of measurements on subsamples. Evaluation of procedural variation ('experimental noise') due to instrumental resolution and handling requires subsampling from homogenous samples.
MitoPedia O2k and high-resolution respirometry: Oroboros QM
Contributed by Gnaiger E 2016-01-27, edited 2016-02-11