Atmospheric concentration (ppm)

CO2= 381

Methane= 1.75

Nitrous oxide= .315

Chlorofluorocarbons= 0.0005

TLS Online TPP Program

#Id: 4616

#Unit 13. Methods in Biology

The total concentration of antibody in the equilibrium dialysis chamber is known, the equilibrium equation can be rewritten as:

TLS Online TPP Program

#Id: 4617

#Unit 13. Methods in Biology

 Scatchard plots are based on repeated equilibrium dialyses with a constant concentration of antibody and varying concentration of ligand. 
If all antibodies have the same affinity, then a Scatchard plot yields a straight line with a slope of Ka. The x intercept is n, the valency of the antibody, which is 2 for IgG and other divalent Igs. For IgM, which is pentameric, n  10, and for dimeric IgA, n  4. In this graph, antibody #1 has a higher affinity than antibody #2.

TLS Online TPP Program

#Id: 4618

#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)

TLS Online TPP Program

#Id: 4619

#Unit 13. Methods in Biology

The bacterium Streptococcus pyogenes, for example, expresses cell-wall proteins called M antigens. Antibodies produced to streptococcal M antigens have been shown to cross-react with several myocardial and skeletal muscle proteins and have been implicated in heart and kidney damage following streptococcal infections. 

TLS Online TPP Program

#Id: 4620

#Unit 13. Methods in Biology

Glycosphingolipids as determinants of blood groups.

TLS Online TPP Program

#Id: 4621

#Unit 13. Methods in Biology

Antibody and soluble antigen interacting in aqueous solution form a lattice that eventually develops into a visible precipitate. Antibodies that aggregate soluble antigens are called precipitins