Anti-Bovine Cell polyclonal antiserum conjugated to fluorescein isothiocyanate Anti-Bovine Cell polyclonal antiserum conjugated to fluorescein isothiocyanate (FITC). Porcine origin. This conjugate is intended to identify or confirm the species of origin of cells or tissues. Cells of bovine origin will fluoresce green when this conjugate is applied per the recommended procedure. Cells of other species origins will not fluoresce above background levels. The recommended method is to mix the test article cells with a benign substrate cell (monkey kidney works fine) in a ratio of 1:15 and place on a slide or microplate culture. FA staining should be done at 1-3 days of culture and fixation should be 100% acetone at room temperature for glass slides, or acetone/water (75/25) for 20 minutes for plastic.