Measurement of albumin in nasal lavage using the technique of chemiluminescent immunoassay.

A method has been developed that uses chemiluminescent acridinium esters rather than radioactive iodine in an immunoassay for albumin. Albumin is a protein derived from plasma sources found in nasal fluids. As such, it can be used as an important marker of plasma exudation in experimental rhinology. The assay was developed as an alternative to radioimmunoassay for a number of reasons: chemiluminescent assays do not require radioactive materials and the complex safety related aspects of their usage; the assays are easy to perform and do not require expensive equipment; and the assay is capable of the sensitivity required to detect very small changes in albumin concentrations in nasal fluids. The assay measures albumin with a sensitivity of 1.2 ng/ml. The working range of the assay is 1.0-23.7 micrograms/ml with an interassay coefficient of variation < or = 15%. This working range encompasses the range of albumin usually found in nasal lavage samples from normal volunteers.