Abstract: 【Abstract】 Objective To detect mite allergens in the dust of air conditioner filter?鄄net and floating air in room. Methods Samples were collected from rooms of asthma patient and normal families with or without air conditioner. Der p 1， Der f 1 and Der 2 were determined by two monoclonal antibody-based ELISA. Results In asthma patient families， the concentration of airborne Der p 1， Der f 1 and Der 2 was （0.23 ± 0.13）， （2.62 ± 1.08）， （0.93 ± 0.41） ng/m³， and （0.56 ± 0.25）， （4.74 ± 1.22）， （2.33 ± 0.64） ng/m³ respectively before and after the air conditioner switched on， all showing a significant difference （P<0.05）. In families without asthma patient， the concentration of Der p 1、 Der f 1 and Der 2 was （0.33 ± 0.11）， （11.50 ± 3.08） and （2.10 ± 0.80） ng/m3， and （0.63 ± 0.23）， （19.80 ± 4.30） and （3.60 ± 1.00） ng/m3 respectively before and after the air conditioner switched on， also showing a significant difference （P<0.05）. From the filter-net dust of air conditioner in family with allergic asthma patient， the concentration of Der p 1， Der f 1 and Der 2 was （0.52 ± 0.19）， （3.34 ± 0.63）， （2.53 ± 0.65） μg/g dust， while that of normal families was （1.30 ± 0.35）， （5.16 ± 0.92）， （3.47 ± 1.13） μg/g dust respectively. The concentration of Der f 1 and Der 2 at both asthma families and normal families was higher than 2 μg/g， an allergen concentration threshold. Conclusion Mite allergens exist in the filter-net dust of air conditioner， which may be an important source of indoor allergens and a cause of the increasing prevalence of allergic asthma.

Key words: House dust mite, Allergen, Air conditioner, Asthma, Floating air