1.
Measurement of IgG1 and IgG4 in purified antibody preparations
| Patients | Fraction | Haemagglutination assay† | |||
|---|---|---|---|---|---|
| IgG1 (ng/ml) | IgG4 (ng/ml) | ||||
| 1 | IgG1 | 781.25 | 0 | ||
| IgG4 | 0 | 24.4 | |||
| 2 | IgG1 | 1200 | <0.1 | ||
| IgG4 | n.d. | n.d. | |||
| 3 | IgG1 | 1200 | 0 | ||
| 4 | IgG4 | 0 | 12.2 | ||
| 5 | IgG4 | 0 | 6.1 | ||
| 6 | IgG4 | n.d. | n.d. | ||
†
Relative concentrations of the IgG subclass proteins were determined by comparison of the haemagglutination titer end-points obtained for the IgG subclass fractions and the corresponding purified monoclonal subclass protein. Subsequently, the IgG subclass fractions were concentrated 90–100-fold by ultrafiltration and used for the cryosection experiments. n.d., not done.