Fig. 2.

Relationship between the viral RNA length and production of lentiviral particles. The quantity of lentiviral particles that are produced (calculated using RT-qPCR) plotted as a function of the viral RNA length (kb). Each point in the plot represents an individual virus batch, each time produced using the pLEGO-DEST backbone and the same transfection method and producer cell line (see Additional file 1: Supplementary Protocol). The viral RNA length is the length of the sequence flanked by the 5′ and 3′ SIN-LTRs in the lentiviral expression vector (see Fig. 1)