Pitfalls in the Assay of Lysozyme in Human Tear Fluid

Abstract

Two assay techniques for lysozyme, the lysoplate and the spectrophotometric procedure, were investigated. With both methods erroneous results may be obtained for human tear fluid lysozyme (HTL), if standardisation is not carried out with the same type of lysozyme; the values obtained from the lysoplates otherwise depend on the properties of the agarose gel, and in the spectrophotometric procedure interference of the rest-absorbance of the assay mixture can disturb the determination when hen egg-white lysozyme (HEL) is used as standard. In the lysoplate procedure the concentration of lysozyme is measured, not the activity as obtained spectrophotometrically.