Radioimmunoassay for desmosine.

A radioimmunoassay was developed for the determination of desmosine. Desmosine conjugated to albumin was injected into rabbits which developed useful titers of serum antibodies after six months. A radioactive probe was prepared with desmosine using [125I]-Bolton-Hunter reagent. Bound desmosine was separated from free desmosine by cellulose acetate filter binding. The sensitivity of the assay is 1-50 picomoles of desmosine. The antibody is highly selective for desmosine, reacting less than 1% with other known crosslinks. Some prepurification may be necessary with complex samples which contain trace amounts of elastin peptides.