2.8. Immunological assays
2.8.1. Lysozyme activity
Lysozyme level was determined by turbidometric assay according
to the method of Ellis [27] with slight modifications. Aliquots
(1.75 ml1
) of Micrococcus lysodeikticus suspension (Sigma)
(0.375 mg ml1
, 0.05 M PBS, pH 6.2) were mixed with 250 ml
1 of
each sample and the optical density was measured after 15 and
180 s by spectrophotometer (Biophotometer Eppendorf) at 670 nm.
PBS was used as a blank and results were expressed according to
amounts of lysozyme (mg) per 1 mg of sample calibrated using a
standard curve determined with hens’ egg white lysozyme (Sigma)
in sterile sodium phosphate buffer.
2