Thyroglobulin and OVA

Thyroglobulin and ovalbumin (OVA) are used less often as carriers, but they are particularly valuable as non-relevant carriers in ELISA tests designed to measure the antibody response 

Since OVA and BSA possess some immunologically similar epitopes, a population of the antibodies produced against one often will cross-react against the other. Therefore, OVA cannot function as a non-relevant carrier for BSA and vice versa. Either OVA or BSA, however, may be used as non-relevant carriers for KLH, thyroglobulin, or the various toxoid proteins used as immunogen conjugates. 

One advantage of OVA is its extreme solubility characteristics in the presence of DMSO. A sparingly soluble hapten molecule may be dissolved in this solvent and added to an aqueous OVA reaction mixture to maintain solubility of the molecule during conjugation. OVA is soluble at up to 70 percent DMSO, becomes cloudy at 75 percent, and precipitates at 80 percent (v/v). 

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