Complex sentence: Ninhydrin can also be used to monitor deprotection in solid phase peptide synthesis, when the growing peptide chain is deprotected, a ninhydrin test yields blue, if the next peptide residue is coupled then the test is colorless or yellow.
Split into simpler sentences: Ninhydrin can also be used to monitor deprotection in solid phase peptide synthesis. If the next peptide residue is coupled then the test is colorless or yellow.