Analysis of the proteins in the latex and WRP of fig tree and rubber tree by 12% (a) and 6% (b) to 17% gradient SDS-PAGE. Rubber particle proteins were solubilized by incubating fig tree WRP in a detergent solution containing 0.1% (w/v) Triton X-100 and 1% (w/v) SDS. After electrophoresis, proteins were detected by Coomassie Blue staining. L, Latex; RP-1, first WRP; RP-2, second WRP; H, rubber tree latex; M, marker.