Salivary lysozyme

Lysozyme is a basic protein composed of a single-chain polypeptide, with a molecular weight of 1.5kD and an isoelectric point of pH11. It is easy to bind to bacteria and can hydrolyze the cell wall of Gram-positive bacteria. It is an important bactericidal substance in body fluids.

Basic Information

Specialist classification: oral examination classification: body fluid examination

Applicable gender: whether men and women apply fasting: fasting

Analysis results:

Below normal:
Pathological reduction is seen in malignant tumors, and salivary lysozyme is reduced to cause oral infection.

Normal value:
Salivary lysozyme: 1.5-1.9mg/L

Above normal:
Found in the dry mouth syndrome (Sjogren's disease).



Tips: Apply warm water to the saliva when collecting saliva, and collect it 5 to 10 minutes after the completion. Normal value

(1.7 ± 0.2) mg / L.

Clinical significance

Reduction: Physiological reduction is seen in women's menstrual period, pathological reduction is seen in malignant tumors, and salivary lysozyme is reduced to cause oral infection.

Elevation: seen in the dry mouth syndrome (Sjogren's disease).

Low results may be diseases: precautions for oral ulcers

1. Salivary lysozyme as a cationic basic protein with enzymatic properties, mainly derived from the prevention of the dissolution of the inducer in saliva when collecting saliva samples so as not to affect the lysozyme activity.

2. When collecting saliva, apply warm water to gargle, and collect it after 5 to 10 minutes. At the time of collection, the catheter can be directly used to draw from the opening of each gland, or the naturally flowing saliva can be collected in a clean test tube. If it is not easy to naturally shed saliva, use a small amount of sterile cotton wool to put it under the tongue for a few minutes, and take out the squeezed cotton ball to get saliva.

Inspection process

The specimens were collected immediately after collection, and the assay methods were precipitation reaction immunoturbidimetry and latex particle passive agglutination immunoturbidimetry.

1. Precipitation reaction Immunoturbidimetric method: When the antibody is excessive, the optimal ratio of antigen and antibody is approximately linear. The antigen-antibody complex turbidity can be determined using an ultraviolet wavelength (340 nm). Most photoelectric colorimeters, spectrophotometers and automatic biochemical analyzers can be used for turbidity.

2. Passive agglutination of latex particles. Immunoturbidimetric method: The antibody is sensitized on the latex particles. When the antigen is added, the sensitized latex particles are combined with the antigen to form agglomerates of different sizes. When the agglomerated particles are small, light can pass; when the aggregated particles are large, the light is scattered and the transmitted light is reduced. Using this principle, two ways of turbidity can be used.

(1) White light emulsion particle turbidimetric method: When the diameter of the latex particle is in the range of 0.1 to 0.8 μm, the particle diameter is large, the absorbance is increased, and the wavelength of about 500 nm is used, and the particle diameter of 0.1 μm can be measured by a wavelength of 585 nm.

(2) Near-infrared light emulsion particle turbidimetric method: the same principle as white light turbidity, the particle size of 0.2 μm latex particles can be measured by 940 nm near-infrared light.

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