Fig 3. The fluorescent dye Alexa 633 successfully conjugates to the kisspeptin after maleimide-based reaction.

HPLC confirmed the successful conjugation of kisspeptin with Alexa 633. Generation of the Alexa 633-kisspeptin probe results in a notable shift in elution time, measured at both 633 nm (A) and 280 nm (B) with no detectable unlabeled peptide. Elution peaks at both wavelengths are identical (C), indicating successful conjugation of the Alexa 633 dye and kisspeptin.