TY - JOUR
T1 - Isotope dilution assay in peptide quantification
T2 - The challenge of microheterogeneity of internal standard
AU - Stoyanov, Alexander V.
AU - Rogatsky, Eduard
AU - Stein, Daniel
AU - Connolly, Shawn
AU - Rohlfing, Curt L.
AU - Little, Randie R.
PY - 2013/12
Y1 - 2013/12
N2 - Isotope dilution analysis allows quantitation of elements and different compounds in complex mixtures. The quantitation is based on a known amount of reference material (internal standard, IS) added to a sample that makes the result critically dependent on the value assigned to the standard. In the case of peptides, IS concentration is determined by nitrogen and amino acid analysis while purity is normally assessed by methods such as chromatography or electrophoresis that might not be able to detect many possible amino acid modifications, either naturally occurring or chemically induced. Microheterogeneity of the IS, if it is not accounted for when assigning a reference value to the standard, results in highly overestimated values in target analyte quantitation. In this viewpoint article, we illustrate the problem of internal standard microheterogeneity by analyzing synthetic human C-peptide labeled analogs.
AB - Isotope dilution analysis allows quantitation of elements and different compounds in complex mixtures. The quantitation is based on a known amount of reference material (internal standard, IS) added to a sample that makes the result critically dependent on the value assigned to the standard. In the case of peptides, IS concentration is determined by nitrogen and amino acid analysis while purity is normally assessed by methods such as chromatography or electrophoresis that might not be able to detect many possible amino acid modifications, either naturally occurring or chemically induced. Microheterogeneity of the IS, if it is not accounted for when assigning a reference value to the standard, results in highly overestimated values in target analyte quantitation. In this viewpoint article, we illustrate the problem of internal standard microheterogeneity by analyzing synthetic human C-peptide labeled analogs.
KW - C-peptide
KW - Isotope dilution assay
KW - Microheterogeneity
KW - Reference material
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U2 - 10.1002/prca.201200130
DO - 10.1002/prca.201200130
M3 - Article
C2 - 23983084
AN - SCOPUS:84890123691
SN - 1862-8346
VL - 7
SP - 825
EP - 828
JO - Proteomics - Clinical Applications
JF - Proteomics - Clinical Applications
IS - 11-12
ER -