Immunochemical quantitation of human submandibular-sublingual lysozyme

A method for quantitating lysozyme by using carbamylated antiserum (commercially available) to human lysozyme in a electroimmunodiffusion technique has been developed. The method measures specific protein not lytic activity as the lyso-plate method does. We have applied this method to tears, parotid saliva, submandibular-sublingual saliva, nasal secretions, serum, and minor salivary gland secretions. We specifically selected submandibular-sublingual saliva for a comparison test with the lyso-plate method because of the known mucin content of the submandibular-sublingual saliva. Our findings indicate that no pretreatment is necessary for the electroimmunodiffusion technique. The lyso-plate method, on the other hand, requires pretreatment with Tris-acetate pH 4.5 to dissociate the mucin-lysozyme complex and give accurate values.