Base calling is the process of assigning bases (nucleobases) to chromatogram peaks. One computer program for accomplishing this job is Phred base-calling, which is a widely used basecalling software program by both academic and commercial DNA sequencing laboratories because of its high base calling accuracy. Base calling is the process of assigning bases (nucleobases) to chromatogram peaks. One computer program for accomplishing this job is Phred base-calling, which is a widely used basecalling software program by both academic and commercial DNA sequencing laboratories because of its high base calling accuracy.