Lowry protein determination by automated flow injection analysis for bovine serum albumin and hepatitis B surface antigen.

The Lowry method for quantitation of protein was adapted to automated flow injection analysis. The procedure was developed using two different pure proteins: bovine serum albumin and hepatitis B surface antigen. The system was optimized for reagent concentration, pH, gain, temperature, sample volume, and output. The response of each protein was affected differently by temperature. The reaction slopes and absorbance values of the proteins were similar at 90 degrees C to allow quantitation of hepatitis surface antigen against bovine serum albumin. Advantages of the automated flow injection analysis Lowry procedure include: rapid analyses (90 samples/h), small sample volume (30 microliters, 100 microliters), fast response (20 s), reproducibility (less than or equal to 2% CV within an assay and 3 to 6% CV among assays), sensitivity (5 micrograms), and high correlation (99.8%) with manual assay. After a 30-min set-up period, the analyzer was available to assay protein on demand throughout the day, making it suitable for process and quality control testing.

Alteration in antibody response induced by carbon inhalation: a model system.

The immune response in mice to antigens given by intraperitoneal, intravenous, and inhalation routes was compared in control and carbon-dust exposed mice. The most pronounced effect, a decrease in antibody-forming cells and serum agglutinin titers, was observed when the carbon-treated animals were immunized with antigens in the form of aerosol. Similar results were obtained when the antigens were administered by intravenous or intraperitoneal route. In contrast 4-days of pre-exposure to carbon dust increased the number of antibody-forming cells in the mediastinal lymph nodes. However, this effect was transient and was not significant when the carbon pre-exposure was continued for 15 days.