The morphological characteristics of the cells were observed by staining with modified Wright–Giemsa stain (Sigma-Aldrich; Merck KGA, Darmstadt, Germany) according to the manufacturer’s protocol.
The phagocytic activity of primary PAMs was determined by adding chicken erythrocytes to a final concentration of 104/mL and incubated for 12 hours. The degree of phagocytosis was then observed under an optical microscope (Nikon Corporation, Tokyo, Japan).
The half maximal inhibitory concentration (IC50) of ricin (Sigma-Aldrich, Corp., St. Louis, MO, USA) was tested by MTS assay (Promega Corporation, Madison, WI, USA). In brief, the cells were grown in 96-well plates and treated with serially diluted ricin (0–105 ng/mL) for 12 hours, followed by the addition of 20 µL MTS to each well. After incubation for 2 hours at 37°C, the absorption was determined at 490 nm. All experiments were performed in triplicate.
The phagocytic activity of primary PAMs was determined by adding chicken erythrocytes to a final concentration of 104/mL and incubated for 12 hours. The degree of phagocytosis was then observed under an optical microscope (Nikon Corporation, Tokyo, Japan).
The half maximal inhibitory concentration (IC50) of ricin (Sigma-Aldrich, Corp., St. Louis, MO, USA) was tested by MTS assay (Promega Corporation, Madison, WI, USA). In brief, the cells were grown in 96-well plates and treated with serially diluted ricin (0–105 ng/mL) for 12 hours, followed by the addition of 20 µL MTS to each well. After incubation for 2 hours at 37°C, the absorption was determined at 490 nm. All experiments were performed in triplicate.