both the igg and f ( ab ' ) 2 immune aggregates bound c3b , the activated form of the complement component c3 , in a similar manner , 2-3 % of the c3 available in the serum being bound to the aggregates as c3b , and the rest remaining in the fluid phase as inactive c3b or uncleaved c3 .
C0009506
complement component c3
C0009511
c3b