I am currently attempting to create a feasible lab design that will enable me to identify the concentration of casein protein in organic milk without having to use spectroscopy. Thus far I have thought of separating the casein from the milk by exploiting its pH of isoelectric point of 4.6 to form curdles and filter the curdles out using a filter. Furthermore, I would rinse and leave the curdles to dry till I am left with casein powder. Following this I would compare the weight of the casein powder to the weight of the original sample of milk I extract it from. Is this a feasible method or are the any other alternative ways also not using any major equipment?