Figure 2. Analysis of membrane immunoglobulin on hybridoma cells. (A) Membrane-bound immunoglobulin on hybridoma and FO myeloma cells was detected by flow cytometry after staining the cells with goat anti-mouse Ig and rabbit anti-goat FITC. (B) Functional antigen-binding of membrane immunoglobulin on 3.3 anti-PEG and anti-β-glucuronidase 7G8 hybridoma cells was detected on a flow cytometer with biotinylated PEG or β-glucuronidase antigens followed by Alexa Fluor 647-conjugated streptavidin. (C) 7G8 anti-β-glucuronidase and 3.3 anti-PEG hybridoma cells mixed at a ratio of 99:1 were stained with 0.5 nM biotin-PEG and Alexa Fluor 647-conjugated streptavidin. Hybridoma cells that bound biotin-PEG (left panel) were collected with a fluorescence-activated cell sorter, cultured for 5 d and then stained with biotin-PEG and Alexa Fluor 647-streptavidin (right panel).