Comparative analysis of DNA from leaf samples conserved in ethanol vs. liquid-nitrogen-frozen controls. (A) λ DNA (50 and 100 ng) followed by non-digested genomic DNA (50 ng) from tropical plant species Jatropha curcas, Theobroma cacao, Coffea arabica, Ricinis communis, Saccharum spp., and Solanum lycopersicon analyzed by 0.8% agarose gel electrophoresis. (B) 1-Kb DNA mass ladder (Fermentas) and 1 μg Eco RI-digested DNA from J. curcas, T. cacao, C. arabica, R. communis, Saccharum spp., and Solanum lycopersicon. N – liquid nitrogen and EtOH – ethanol. (C) 100-bp DNA ladder molecular weight marker (Fermentas) and ITS PCR amplification products of the same plant species.