This microarray serie represents the complete gene expression study of bacteriophage BFK 20 during the infection of its host Brevibacterium flavum CCM 251. Keywords: time course Overall design: Gene expression was measured at fourteen time intervals (0, 1, 3, 5, 7, 10, 15, 20, 30, 40, 50, 60, 80 and 120 min) during phage infection according to proposed loop. Each sample was directly compared to the previous and to the next sample (point of total RNA isolation).