English: A representative live cell imaging and tracking of cytoplasmic progeny vRNP signals. Live cell imaging of infected MDCK cells (Figure 1A) was carried out as described in the Materials and Methods section. Acquired images were processed, analyzed, and encoded to a movie containing concatenated four parts. The first color part contains 25 of merged images (red, mAb61A5 channel; green, control antibody channel). Each of single channel images was acquired alternately at 250 ms exposure. The second gray-scale part contains 100 images acquired at 250 ms exposure for 25 seconds at single mAb61A5 channel, immediately after the dual-color acquisition. The third part of the movie is post-processing images of the second part. The image processing procedure was described in the Materials and Methods section. The last part is the signal tracking by using ImageJ software and MTrackJ plugin (created by Eric Meijering, http://www.imagescience.org/meijering/software/mtrackj/). Individual signals were tracked manually (90 tracks). Track numbers, trajectories, and current position of vRNP signals were indicated on the post-processing images with numerals, colored lines, and blank circles, respectively. Elapsed times were also indicated.