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Electron microscopic images of isolated polyvalent phages. Panels depict phages PX1 (Podoviridae) (A), PPJ2 (Podoviridae) (B), PEa1 (Siphoviridae) (C), and PEf1 (Siphoviridae) (D). Phages were negatively stained with 2% uranyl acetate. Bar, 50 nm.
