Coloured TEM of T4 bacteriophage infecting E. coli (M090/0075) Tapestry

Bacteriophage. Coloured transmission electron micrograph of a T4 bacteriophage (orange) after injecting its viral DNA into the Escherichia coli bacterium (blue). Bacteriophages are viruses that infect bacteria; T4 is specific to E.coli. It is secured to the surface of the cell by spidery tail fibres. The tail, a contractile sheath, shortens to allow a syringe-like tube (below base plate of tail) to enter the cell membrane, emptying the DNA contents of the head into the bacterium. The capsid, a protein coat surrounding the DNA, stays outside. Phage' synthesis in the cell follows rapidly. Magnification: X65,000 at 6x7cm size. magnification: x220,000 at 10x8 size.