Table 1.

Similarities and differences between LPPS and SPPS. Parameters taken into account for comparison of the two techniques are report in bold in the first column on the left.

	Liquid-Phase Peptide Synthesis (LPPS)	Solid-Phase Peptide Synthesis (SPPS)
Medium	Solution	Insoluble polymer
Batch size	Any (usually large scale)	Any (usually small scale)
Timing	Slow	Fast
Automation	Difficult	Semi- or fully-automated
Synthetic strategy	Generally convergent	Stepwise
Protecting groups employed	Typically Boc or Z	Typically Fmoc
Side-chain protection	Minimum	Maximum
Consumption of AA	Moderate	High
In-process analysis	Direct monitoring (e.g., HPLC)	Indirect monitoring
Purification of intermediates	Possible (usually by precipitation)	Not possible
Final purification	Relatively simple	Laborious