Send to

Choose Destination
Anal Biochem. 2009 Feb 1;385(1):101-6. doi: 10.1016/j.ab.2008.09.053. Epub 2008 Nov 1.

Comparison of different approaches for evaluation of the detection and quantitation limits of a purity method: a case study using a capillary isoelectrofocusing method for a monoclonal antibody.

Author information

Analytical and Formulation Sciences, 1 Amgen Center Drive, M.S. 30E-1-C, Amgen, Thousand Oaks, CA 91320, USA.


Several different techniques suggested by the International Conference on Harmonization (ICH) Q2R1 guideline were used to assess the signal and concentration at the limit of detection (LOD) and limit of quantitation (LOQ) for a purity method. These approaches were exemplified with a capillary isoelectrofocusing (cIEF) method, which has been developed to quantify the distribution of the charge isoforms of a monoclonal antibody. The charge isoforms are the result of incomplete posttranslational processing of C-terminal lysine residues of the heavy chain by carboxypeptidase. Results showed no significant discrepancy between LOD/LOQ obtained by the different techniques. Validation experiments corroborated the calculated LOQ. The results indicate that any single technique can provide meaningful values for the LOD and LOQ. Finally, important points to consider when applying these techniques to purity methods are discussed.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center