A Quantitative Micro-Complement Fixation Method in Studies of Human Wart Viruses

This paper describes a quantitative micro-complement fixation method for detecting human wart virus antigens and their specific antibodies. The researchers adapted Cikes' micro-complement fixation technique, which uses chromium-51 labeled sheep red blood cells to measure unbound complement through radioactive release, providing greater sensitivity than visual interpretation alone. Guinea pig complement, sensitized sheep erythrocytes, and monospecific rabbit antisera against human hand wart virus were used in microplate reactions. Testing included wart tissue suspensions, plantar wart samples, and infected tissue culture cells. Results showed that radioactive analysis revealed antigen titers 4-8 fold higher than visual reading, particularly for tissue culture materials with low virus antigen levels. Cross-absorption studies confirmed specificity: undiluted antisera reacted strongly with wart virus but not uninfected skin; absorption with wart virus antigen removed all detectable activity, while absorption with normal skin did not. No cross-reactivity occurred with other Papova viruses. The technique's increased sensitivity and specificity make it suitable for quantifying wart virus antigens in clinical and research samples.

Key findings

• Micro-complement fixation using chromium-51 labeled red blood cells provides 4-8 fold greater sensitivity than visual interpretation for detecting wart virus antigens
• Radioactive measurement analysis is particularly valuable for detecting low levels of virus antigen in tissue culture materials
• Cross-absorption studies confirm the reactions are specific to human wart virus, with no cross-reactivity to other Papova viruses like SV40, BK, or JC virus
• The monospecific antisera distinguished wart virus antigens from normal skin components through selective absorption studies