A microassay for the determination of hemolytic complement activity in mouse serum

Area of Science:

• Immunology
• Biochemistry
• Assay Development

Background:

• Complement activity in mouse serum is crucial for immune responses.
• Existing methods for measuring complement activity can be complex or require large sample volumes.

Purpose of the Study:

• To develop and validate a simple, reproducible microhemolytic complement assay for mouse serum.
• To compare the efficiency of IgG and IgM antibodies in the assay.
• To establish baseline hemolytic complement values for different mouse strains.

Main Methods:

• A 51Cr release microhemolytic assay using antibody-sensitized sheep erythrocytes (SRBC).
• Mouse serum as the complement (C) source was added to sensitized SRBC in microtiter plates.
• Quantification of 51Cr release to determine hemolytic activity.

Main Results:

• The 51Cr release assay effectively detects hemolytic complement activity in mouse serum.
• 7S IgG antibody demonstrated higher efficiency than 19S IgM antibody in the lytic assay.
• The assay requires small serum volumes and is reproducible across different murine strains.
• No correlation was found between H-2 type and hemolytic complement levels in inbred mouse strains.

Conclusions:

• A novel, efficient, and sensitive microhemolytic complement assay for mouse serum has been established.
• The assay provides a valuable tool for immunological research involving mouse complement.
• IgG is a more effective antibody isotype for this specific complement-mediated lysis assay.