[Description and validation of a flow cytometric method to estimate residual leukocytes in leukocyte-depleted red cell concentrates]. / Description et validation d'une méthode cytofluorométrique d'estimation des leucocytes résiduels dans les concentrés globulaires déleucocytés.

We describe a flow-cytometric method for estimating residual white blood cells (WBC) counts in WBC depleted blood components, namely units of packed red cells. The method uses fluorescent staining of nuclear ADN with ethidium bromide. WBC nuclei are discriminated from background events using fluorescence ratio (585 nm versus 650 nm). A facultative procedure of concentration is described, in order to get better sensitivity at very low WBC counts. Main steps of validation are dilution assays and correlation with hemocytometer counts. The method can be used to explore very low concentrations (less than 100 WBC/ml) and should be useful in quality control of blood products.

Instantaneous roll-blot from cellulose acetate after electrophoresis. A versatile tool for monoclonal antibody characterization.

An instantaneous blotting method from cellulose acetate to nitrocellulose was developed using a high pressure roll apparatus. This method was applied to the early characterization of monoclonal antibody specificity and to monoclonal immunoglobulin typing in mouse hybridoma supernatants, human sera or unconcentrated urines. Immunoglobulins were then revealed using, successively, anti-isotype specific monoclonal or polyclonal antibodies, avidin-biotinylated peroxidase complexes and cobalt-enhanced diaminobenzidine substrate.