ABSTRACT

References ........................................................................................................ 582

The first method used in the discovery of cell-penetrating peptides (CPPs) was

microscopy on fixed cells and indirect labeling of biotinylated peptides.1 Since then,

a number of different methods have been developed for the study of these

versatile peptides. Furthermore, the initial method of detection in fixed cells has

been reevaluated and it was shown that, in some cases, the intracellular distribution

can be overestimated in fixed cells.2,3 The detection of intracellular CPPs poses

several other problems; for example, the difficulty of distinguishing membrane

bound CPP from cytoplasm localized CPP. In this chapter, the most widely used

methods in detecting and quantifying the translocation of CPPs will be reviewed, as

well as the quantification of a few cargoes delivered by CPPs.