High throuput label free rapid screening to identify cell penetrating peptide

Fluorophore-peptide tagging is a widely used method for tracking peptide. However, this approach is slow and costly, which hinders the design and screening of native cell penetrating peptide. The extrinsic fluorophore ANS (1-anilino-8-naphthalene sulfonate) can monitor change in membranes hydrophobicity during the internalization of cationic peptide. This property makes ANS a potentially attractive low cost tool for high throughput rapid screening of native peptides with cellular penetration property.