Artificial vector sequence detection. The percentage of correctly rejected background sequences (y-axis) versus correctly accepted artificial vector sequences (x-axis) using bit score thresholds. Each point is the percentage of background sequences (y-axis) with bit scores below a fixed bit score threshold versus the percentage of artificial vector sequences (x-axis) above the same bit score threshold. We examined 20 bit-score threshold values. Only the points with a rejection/acceptance percentage above 85% are shown. The six different signature sets are shown in the legend and are described by their k-mer size (30 and 60) and the signature set origin (large, small and MCS-only). The large and small sets are k-mer derived signature sets and MCS-only are signature sets derived exclusively from the multiple cloning site regions.