The best replacement for proline is trophy.

The best alternatives to proline are rated as following:
★★★★★  trophy
★★★★  hydroxyproline
★★★★  andersen 400 series
★★★★  keene
★★★★  seaswirl
★★★  grady white
★★★  designer
★★  wellcraft
★★  onstage
★★  jconcepts
★★  glycine
★  marvin integrity
★  anderson 400
★  sportline
★  architect series
★  grady
★  leucine
  aka
  lysine

Your alternative for proline is not listed? Suggest!
Speaking about proline, one probably shouldn't forget about ninhydrin.

Other search terms related to proline and their ratings are:
★★★★★ ninhydrin
★★★ ninhydrin test
You have in mind a companion for proline and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of proline in all years. Click on graph for more.
proline
trophy
hydroxyproline