Division 2.3.5 Calculation of resultsF1F2F3
United Kingdom
The OIEISS contains 1 000 international CFT units (ICFTU) per ml. If the OIEISS is tested in a given method the result is given as a titre (i.e. highest direct dilution of the OIEISS giving 50 % haemolysis, T OIEISS ). The test result for the test serum given as titre (T TESTSERUM ) must be expressed in ICFTU per ml. In order to convert the expression of a titre into ICFTU, the factor (F) necessary to convert a titre of an unknown test serum (T TESTSERUM ) tested by that method into the ICFTU expression can be found from the formula:
F = 1 000 × 1/T OIEISS
and the content of international CFT units per ml of test serum (ICFTU TESTSERUM ) from the formula:
ICFTU TESTSERUM = F × T TESTSERUM