[Precision intra-assay study in the absence of internal quality control: example of radioimmunoassay of procollagen III peptide].

The first step to complete in a method validation of a biological analysis is the study of precision intra-assay. In the absence or insufficient quantity of control material, this study may be difficult to perform. This article proposes a methodology for preparing its own control samples for the radioimmunological assay of the amino-terminal peptide of procollagene type III (PIIIP). This methodology is easy to carry out, cost-effective and can be applied to analyses other than PIIIP. Furthermore, it allows the execution of control samples which have similar concentrations of analytes to those described in the precision studies of the datasheets provided by the manufacturers.