Patent ID: 7981681

Claim:
A method for the automatic analysis of a blood sample comprising: forming an analysis solution in a first tank, said first tank being a dilution and analysis tank, the dilution rate of the analysis solution being comprised between 1/100 1/500 th , said solution containing: said blood sample, a diluent, a mono-reagent including at least one compound to lyze erythrocytes in said blood sample, at least one compound to stabilize haemoglobin in said blood sample as oxyhaemoglobin, and at least one leucoprotective compound to protect leucocytes in said blood sample to allow distinguishing of at least five main leucocyte sub-populations, said leucoprotective compound being selected from the group consisting of betaines and sulphobetaines of quaternary amnoniums, tertiary amine oxides, glycosidic compounds and glucidic compounds; measuring haemoglobin level in the analysis solution by spectrophotometry in said first tank after the lysis of the erythrocytes; and sampling an appropriate quantity of the analysis solution from said first tank and carrying out by optical means a leucocytic differentiation of at least five sub-populations on the sampling of the analysis solution, wherein the optical means includes a flow cytometer in which a sleeving flow is provided around a sample flow containing the sampling of the analysis solution, the sleeving flow being passive in that it does not stretch the sample flow.