Metal-coded affinity tag

Metal-coded affinity tag is a method used for quantitative proteomics by mass spectrometry that uses a metal chelate complex 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) coupled to different lanthanide ions.{{cite journal|last1=Ahrends|first1=R.|last2=Pieper|first2=S.|last3=Kuhn|first3=A.|last4=Weisshoff|first4=H.|last5=Hamester|first5=M.|last6=Lindemann|first6=T.|last7=Scheler|first7=C.|last8=Lehmann|first8=K.|last9=Taubner|first9=K.|last10=Linscheid|first10=M. W.|title=A Metal-coded Affinity Tag Approach to Quantitative Proteomics|journal=Molecular & Cellular Proteomics|volume=6|issue=11|year=2007|pages=1907–1916|issn=1535-9476|doi=10.1074/mcp.M700152-MCP200|pmid=17627934|doi-access=free}}{{cite journal|last1=Messana|first1=Irene|last2=Cabras|first2=Tiziana|last3=Iavarone|first3=Federica|last4=Vincenzoni|first4=Federica|last5=Urbani|first5=Andrea|last6=Castagnola|first6=Massimo|title=Unraveling the different proteomic platforms|journal=Journal of Separation Science|volume=36|issue=1|year=2013|pages=128–139|issn=1615-9306|doi=10.1002/jssc.201200830|pmid=23212829}} The metal complexes attach to the cysteine residues of proteins in a sample.