Correctly formulated solution to ensure consistent mastitis testing. (Non-professional solutions can give varying results.) Generally testing requires 1 litre per 50 cows. Solution is added to the RMT paddle in at least the same amount as the milk. Ideally the solution is used from a squirt or pump bottle. RMT solution is non-toxic, but is coloured blue for easy identification. Coagulation of the milk sample indicates the presence of somatic cells in high concentration.