Abstract: Improvement in the preparation of allergens, for the obtention of more stable and more effective preparations from extracts of various materials such as pollens, house dust, kapok, wool, molds, etc. extracts containing only allergenic substances having molecular weights in the range of from about 10,000 and 50,000 and being free from enzymes are broadly contemplated.The substances have no allergenic activity are removed from the aqueous extract. In particular, molecular masses below 14,000 and above 45,000 are eliminated.The allergen thus improved is suitable in the adsorbed form, for example, on alumina and phosphates of aluminum or of calcium; it provides particularly good results when the adsorbent is a special phosphate in which the ponderal ratio Ca/P is 1.55 to 1.90.

Abstract: The invention involves a process of preparing purified stable allergens from various materials.