Hepatitis B surface antigen assembles in a post-ER, pre-Golgi compartment

Autoradiographs from the pulse-chase experiments were digitized with Sony XC-77CE CCD camera module with a CCTV 12.5-75 FI.9 zoom lens connected to Apple Macintosh Ilcx microcomputer via a DT2255-50 Hz card (Data Translation Inc., Marlboro, MA) using Image 1.40 image processing and analysis program (Wayne Rasband, National Institute of Health, Research Services Branch, Bethesda, MD). 16 frames were averaged into one TIFF-format file. The optical densities of individual protein bands on the autoradiographs were quantitated as peak areas in pixels from column average plots using the Image 1.40 program.