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Cell-Dyn 3500 automate (Abbott) provides reticulocyte count using a recent software, after ribosomal RNA colouring with methylene blue reagent. The aim of this study was to evaluate results from Cell-Dyn 3500, and to compare them with the routine laboratory technique by flow cytometry (FacScan, Becton-Dickinson). Cell-Dyn 3500 analytical parameters (inter- and intra-assay precision, sample-to-sample contamination) were good and in accord to manufacturer's specifications. Reticulocyte values from blood samples kept at 4 degrees C during 3 days were unchanged. Usual values in 145 normal patients were found between 71.3 and 78.3 G/l with Cell-Dyn 3500, between 119.3 and 130.2 G/l with FacScan. Both techniques were compared in 87 patients with various anemias: Cell-Dyn 3500 showed more frequently high reticulocyte values in regenerative anemias (hemorrhagic), but was less performant for classification of aregenerative anemias. Reticulocyte count with Cell-Dyn 3500 is a semi automatic, easy to perform and swift technique, using no toxic reagent but unitary test tubes kept at room temperature. The test cost is however high, and Cell-Dyn 3500 cannot be used during the analysis.

Here we report on our experience with the use of a 'Gel-Test' (DiaMed-ID Micro Typing System) technique for the detection and identification of irregular antibodies in a general hospital. This easy-to-use, standardized technique poses the question of the impact of its sensitivity on the specificity of the results. Of the 10% of observed positive reactions, 3.7% were irregular antibodies, 3.8% papain auto-antibodies, 1% cold antibodies and 2% not elucidated. Two hundred and eighteen irregular antibodies identified and titred with the 'gel-test' system were tested in parallel by 'tube' method. Sixty-three of these antibodies (29%) were not detected by the 'tube' method. While anti-Kell was always detected by both methods, we found the following false natives with the tube method: 15% anti-D, 32% anti-E, 42% anti-Cw and 58% anti-Lea. 68% of these false negatives had a low titre. The immunoglobulin class of the anti-E was studied; the sensitivity of the 'gel-test' system was associated with IgM in the anti-E. The sensitivity and standardization of the 'gel-test' technique guarantee greater safety in blood transfusion and increase efficiency in the prevention of foeto-maternal stimulation of anti-D.

Fibrinopeptide A becomes free after thrombolysis of fibrinogen in thrombo-embolic situation. In view to quantify this molecule, the authors have compared two different methodologies (enzymatic and isotopic). Isotopic scintigraphy of lung (ventilation-perfusion) served as reference in this study for pulmonary thrombosis.

2 mercapto-ethanol (2 M-E) can be used to demonstrate IgM immunoglobulins to both toxoplasmosis and to measles, but while the action of this reagent is easily confirmed in the course of agglutination reactions with toxoplasma, it is only straightforward in certain circumstances in the course of the inhibition of haemagglutination reaction with measles virus. The agglutination reaction is very sensitive for this group of immunoglobulins: the depolymerization of toxoplasmosis IgM by 2 M-E is well demonstrated in total serum. The inhibition of haemagglutination reaction is sensitive for IgM and IgG, but the much higher concentration of IgG often masks the immunological activity of the IgM; the depolymerization of measles IgM by 2 M-E is only barely demonstrated on the IgM fraction. The use of 2 M-E is also a valuable means of confirming the fractionation obtained by filtration chromatography.