TABLE 1.
Precipitation reactions of inorganic salt solutions used for simulating antigen-antibody reactions of the Ouchterlony double immunodiffusion assay
| Spur identity | Center well (simulated antibody) | Outer wells (simulated antigen) | Precipitation reaction at the equivalence zone (antibody + antigen → immune complex product) | Example figure |
|---|---|---|---|---|
| Full identity | AgNO3 | NaCl | AgNO3 (aq) + NaCl (aq) → NaNO3 (aq) + AgCl (s) | Fig. 2A |
| Partial identity | BaCl2 | AgNO3 | 2AgNO3 (aq) + BaCl2 (aq) → Ba(NO3)2 (aq) + 2AgCl (s) | Fig. 2B |
| MgSO4 | MgSO4 (aq) + BaCl2 (aq) → MgCl2 (aq) + BaSO4 (s) | |||
| Partial identity | BaCl2 | AgNO3 | 2AgNO3 (aq) + BaCl2 (aq) → Ba(NO3)2 (aq) + 2AgCl (s) | Fig. 2C |
| CuSO4 | CuSO4 (aq) + BaCl2 (aq) → CuCl2 (aq) + BaSO4 (s) | |||
| Partial identity | BaCl2 | AgNO3 | 2AgNO3 (aq) + BaCl2 (aq) → Ba(NO3)2 (aq) + 2AgCl (s) | Fig. 2F |
| MnSO4 | MnSO4 (aq) + BaCl2 (aq) → MnCl2 (aq) + BaSO4 (s) | |||
| Nonidentity | AgNO3 | Na3PO4 | NH4Cl (aq) + AgNO3 (aq) → NH4NO3 (aq) + AgCl (s) | Fig. 2D and E |
| MnSO4 | NH4Cl | 2Na3PO4 (aq) +3MnSO4 (aq) → 3Na2SO4 (aq) + Mn3(PO4)2 (s) | ||
| No precipitation | Any salt | H2O | No precipitation reactions occur with water | Fig. 2A, B and F |