Editing Proteomics (section)

=== Antibody-free protein detection ===
While protein detection with antibodies is still very common in molecular biology, other methods have been developed as well, that do not rely on an antibody. These methods offer various advantages, for instance they often are able to determine the sequence of a protein or peptide, they may have higher throughput than antibody-based, and they sometimes can identify and quantify proteins for which no antibody exists.

==== Detection methods ====
One of the earliest methods for protein analysis has been [[Edman degradation]] (introduced in 1967) where a single [[peptide]] is subjected to multiple steps of chemical degradation to resolve its sequence. These early methods have mostly been supplanted by technologies that offer higher throughput.{{citation needed|date=April 2023}}

More recently implemented methods use [[mass spectrometry]]-based techniques, a development that was made possible by the discovery of "soft ionization" methods developed in the 1980s, such as [[matrix-assisted laser desorption/ionization|matrix-assisted laser desorption/ionization (MALDI)]] and [[electrospray ionization|electrospray ionization (ESI)]]. These methods gave rise to the [[Top-down proteomics|top-down]] and the [[bottom-up proteomics]] workflows where often additional separation is performed before analysis (see below).

==== Separation methods ====
For the analysis of complex biological samples, a reduction of sample complexity is required. This may be performed off-line by [[SDS-PAGE|one-dimensional]] or [[Two-dimensional gel electrophoresis|two-dimensional]] separation. More recently, on-line methods have been developed where individual peptides (in bottom-up proteomics approaches) are separated using [[reversed-phase chromatography]] and then, directly ionized using [[electrospray ionization|ESI]]; the direct coupling of separation and analysis explains the term "on-line" analysis.