sentence: The identity of this band was confirmed by an ∼ 4000 bp product obtained in a reaction with a 517 bp BIV RU5 substrate ( Figure 3C , lane 4 ) and by the characteristic triplet at ∼ 3400/3700 / 4000 bp revealed when both RU5 and RU5 BIV substrates were used in one reaction ( Figure 3C , lane 5 ) .