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Protein values of dialysed allergen extracts determined by Lowry, modified Lowry (trichloroacetic acid precipitation of the proteins) and dye-binding assay were compared. The influence of different parameters on the modified Lowry was examined. The reproducibility of the modified Lowry was checked with three independent measurements. For the examination of recovery a constant amount of 6-grass pollen allergen proteins was added to the samples of the standardized human serum albumin prepared for the calibration curve. The samples were measured by modified Lowry. The mean of the ratio between the protein values of the dialysed allergen extracts obtained by modified Lowry and those obtained by classical Lowry was 3.59 (coefficient of variation C v = 45%). The mean of the ratio between the protein values of the allergen extracts obtained by modified Lowry and dye-binding assay was 1:0.71(C V = Phenol interfered with the modified Lowry. Phenolic allergen extracts showed higher "protein values" than non-phenolic allergen extracts. This influence could be reduced by a second precipitation of the dissolved precipitate. The precipitation of non-phenolic dialysed aqueous allergen extracts was complete after the first trichloroacetic acid precipitation. By incubating samples with the Folin-Ciocalteu's reagent at 55 °C in a waterbath, the time necessary for developing the colour could be reduced from 45 min to 5 min. Protein measurements by modified Lowry of a 6-grass pollen allergen extract in three different laboratories showed good reproducibility. For these extract 785 Mg protein/ m/ (C v = 4%) could be measured. The addition of a constant amount of allergen proteins to the samples prepared for the human serum albumin calibration curve produced a curve parallel to this calibration curve. Vergleich der klassischen und der modifizierten Proteinbestimmung nach Lowry und des "dye-binding assay" zur Analyse von Allergenextrakten und Untersuchung des Einflusses von unterschiedlichen Bedingungen auf die Proteinbestimmungsmethode nach dem modifizierten Lowry-TestZusammenfassung: Die Proteinwerte von dialysierten Allergenextrakten wurden mit der Proteinbestimmungsmethode nach Lowry, modifiziertem Lowry-Test (Trichloressigsäurefällung der Proteine) und "dye binding assay" ermittelt und miteinander verglichen. Der Einfluß von unterschiedlichen Versuchsbedingungen auf den modifizierten Lowry-Test wurde untersucht. Die Reproduzierbarkeit des modifizierten LowryTests wurde in drei unabhängigen Messungen überprüft. Zur Durchführung eines Wiederfindungsexperimentes wurde eine konstante Menge Protein eines 6-Gräserpollen-Allergenextraktes zu den Proben gegeben, die für die Humanserumalbumin-Kalibrierungskurve hergestellt wurden. Der Mittelwert des Verhältnisses der Proteinwerte, der bei den dialysierten Allergenextrakten mit dem modifizierten und dem klassischen Lowry-Test gemessen wurde, betrug l: 3.59 (Variationskoeffizient C v = 45%). Der Mittelwert des Verhältnisses der Proteinwerte, der bei den Allergenextrakten mit dem modifizierte...

Detailed studies of the boundary layer profile and the characteristics of the flow velocity distribution close to the leading edge of a helicopter blade profile were conducted using the embedded laser doppler velocimetry (ELDV) and stereo-PIV. The relatively small scales of flow structures related to dynamic stall, motivated an additional 2C-PIV study in which the flow field has been measured with a relatively high spatial resolution. The feasibility of PIV measurements utilizing a mirror telescope in a wind tunnel has been demonstrated successfully. The spatial resolution of approximately 50 µm allowed a judgment on the choice of turbulence models and damping coefficients for the improvement of CFD predictions.