The uptake of five fluorescein labeled cell-penetrating peptides (Tat, Tat2, mutated-Tat, peptide vascular endothelial-cadherin and transportan) was studied in wheat immature embryos. Interestingly, permeabilization treat-ment of the embryos with toluene⁄ethanol (1 : 20, v⁄v with permeabiliza-tion buffer) resulted in a remarkably higher uptake of cell-penetrating peptides, whereas nonpermeabilized embryos failed to show significant cell-penetrating peptide uptake, as observed under fluorescence microscope and by fluorimetric analysis
