Method for Depletion of IgG and IgM from Human Serum as Naive Complement Source

Area of Science:

• Immunology
• Biochemistry

Background:

• Human complement proteins are crucial for antibody therapies and understanding autoimmune diseases.
• Baby rabbit serum is commonly used as a complement source, but human serum is preferred for human antibody characterization.
• Naturally occurring IgG and IgM in human serum can interfere with complement studies.

Purpose of the Study:

• To develop a method for depleting human serum of naturally occurring IgG and IgM.
• To preserve complement activity during the depletion process.
• To validate the depletion and assess remaining complement function.

Main Methods:

• Fast protein liquid affinity chromatography (FPLC) was employed for IgG and IgM depletion.
• IgG, IgM, and C1q sandwich ELISAs were used to validate antibody depletion.
• Hemolytic assays (CH50 and AH50) were performed to assess residual complement activity.

Main Results:

• FPLC effectively depleted human serum of IgG and IgM.
• The depletion method minimized the loss of essential complement activity.
• Validation assays confirmed successful IgG and IgM removal and functional complement activity.

Conclusions:

• Depleted human serum provides a valuable resource for antibody-based research and therapeutic development.
• The described method offers a reliable way to prepare human serum for complement studies.
• Purification of captured IgG and IgM is also demonstrated, offering further utility.