: Best for proteins > 10 kDa and highly hydrophobic peptides.

: The protein sample is aspirated through the tip, binding to the C4 resin.

: Enrichment of dilute samples to ensure they are within the detection range of highly sensitive instruments. Role in Mass Spectrometry

Expression, Purification and Characterization of the Human ... - Nature

: Typically optimized for very small volumes (microliters).

: Removing salts, buffers, and detergents that interfere with downstream analysis. For example, researchers use them to clean samples of Trastuzumab probes or mussel biotoxins before testing.