Reagent paper strips for the determination of acetone in urine. They are an excellent aid for the diagnosis of Ketonuria or Ketonemia. It allows the patient to determine for himself, in a simple, comfortable and sufficiently precise way, the proportion of acetone (ketone bodies) present in the urine. Use fresh urine, collected in a perfectly clean container. Dip the reagent end of the strip into the urine, following the direction of the arrow. It can also get directly wet in the urine. Remove immediately and wait about 15 seconds. Compare the color obtained in the strip with the colored scale that appears on the label of the container, with which you will have an appreciation of the amount of acetone present in the urine. The comparison should be made in good light, and ideally in daylight. Store the tube in a cool, dry place. Do not touch the impregnated end of the strips with your fingers. Protect the strips from moisture: keep the tube tightly closed with its original cap, which has a desiccant inside and separating only the strips to be used. The colors obtained when the 15 seconds have been greatly exceeded are not comparable. Despite their good stability, if the above warnings are not followed exactly, and especially if the environment is excessively humid, the inter-acetone strips may lose activity. In the latter case, the end of the reagent paper acquires a strong yellow color, and then it is advisable to discard them.