Figure 4. Agarose gel electrophoresis of PCR amplified DNA fragments of cotton leaf crumple virus (CLCrV) DNA A. Each lane represents DNA products from 10 ng of total cotton DNA amplified for 40 cycles. BRL 1 kb standard (lane 1). Total DNA preparations from CLCrV-diseased (lanes 2 and 5) and healthy (lanes 3 and 6) tissues were amplified with either primer pair F500 and R1800 (lanes 2 and 3) or primer pair R500 and F1800 (lanes 5 and 6). As controls, PCR reactions with no DNA template were carried out with the primer pair F500 and R1800 (lane 4) and the primer pair R500 and F1800 (lane 7). Lane 8 shows total cotton DNA extracted as described in Materials and Methods. PCR amplified DNA fragments and total DNA were analysed by electrophoresis in a 0.8% agarose gel.