Ascoli reaction

Ascoli reaction is the reaction of precipitation (thermoreceptor) to detect anthrax or antigen in a variety of substrates (leather, wool, felt, bristles, cloth, meat, earth, faeces animal, and so on). From the study material is prepared by boiling within 5-45 minutes hood in izotonicescom solution of sodium chloride or extracted antigen 0,5% carbolic or acetic acid in izotonicescom solution of sodium chloride. The extract was filtered through filter paper or asbestos wool or centrifuged at 1000-3000 rpm Into a narrow tube precipitation pour immune precipitating protivovirusnuu serum and carefully applied her subject extract. In the next 10 minutes on the border between serum and extracts in positive cases, there is a ring of turbidity (colcapitical). Ascoli reaction is very sensitive and specific. With its help it is possible to quickly identify materials infected with anthrax. Cm. also Precipitation, Serological studies, anthrax.

Ascoli reaction (A. Ascoli - diagnostics reaction precipitation used for the diagnosis of anthrax. Is detected in the tested material thermostable anthrax antigen using precipitating anthrax serum. The pieces of bodies, skins, skin, coat of dead animals, sometimes meat, sausage and dairy products, extracts from the land contaminated pastures and burial sites, fodder grind, pour triple the amount of 0.5% solution 80% acetic acid in the physiological solution of NaCl and extracted for 10-15 minutes in the device Koch or autoclave at temperature of 110 degrees. Extract neutralize, filtered to full transparency through dense paper filter or annealed asbestos wool. The presence of anthrax antigen reveal several layers of extract drawn Pasteur pipette to precipitating the serum in the narrow tubes in the volume of 0.5 ml Convenient to use a special tubes Ascoli (Fig). With a positive reaction on the border between serum and extracts immediately or within 5 - 10 minutes circle appears blurred, becoming more intense. The results are checked by the control samples (see table).

No. of tubes (sample) Contents of a test tube
1 Precipitating serum + extract of the studied material
2 Precipitating serum + extract from the spleen obviously anthrax animal
3 Precipitating serum + extract agar culture of anthrax
4 Precipitating serum + extract of material taken from a healthy animal
5 Precipitating serum + physiological solution NaCl
6 Normal serum + extract of the studied material
7 Normal serum + extract from the spleen obviously anthrax animal
8 Normal serum + physiological solution NaCl

In test tubes № 4, 5, b and 7 rings opacities are missing. A. R. you can put it shorter: sample 1, 2, 5 and 6.

The device for the reaction Ascoli: 1 - funnel; 2 - filter; 3 - capillary tube; 4 - extract; 5 - ring precipitation; 6 - serum.