#Id: 4668
#Unit 13. Methods in Biology
If the antibody preparation is polyclonal and has a range of affinities, Scatchard plot yields a curved line whose slope is constantly changing. The average affinity constant K0 can be calculated by determining the value of Ka when half of the binding sites are occupied (i.e., when r 1 in this example). In this graph, antiserum #3 has a higher affinity (K0 2.4 108) than antiserum #4 (K0 1.25 108)
