The invention relates to a method for determining the activity of a component of the electron transport chain or any associated protein thereof and for determining the effect of a compound on the activity of a component of the electron transport chain or any associated protein thereof. The invention also relates to a kit comprising a redox probe, at least one electron donor compound of a component of the electron transport chain or a protein associated thereof and optionally comprising a sample comprising mitochondrial membranes and to the use of said kit in the methods of the invention.

A granule for detecting glucose in pet urine, includes: 80-100 parts by weight of a filler, 30-50 parts by weight of water-absorbent material, 2-4 parts by weight of a bacteriostatic agent, 5-10 parts by weight of an adhesive, 1-2 parts by weight of glucose oxidase, 2-4 parts by weight of peroxidase, 2-6 parts by weight of an indicator.