Anti-picryl suppressor factor was prepared in the standard way, i.e. by culturing lymphoid cells from mice injected with picrysulphonic acid and then painted with picryl chloride and taking the supernatant fluid. It was assessed by its ability to depress the passive transfer of contact sensitivity by immune cells incubated in it. The factor can be specifically absorbed by picryl (but not oxazolone) albumin sepharose beads and can be specifically eluted by picryl (but not oxazolone) ε-aminocaproic acid and by picryl-ε-N-lysine. These findings emphasise the role of the hapten epitope in the binding of a specific T cell product.
The factor can also be absorbed by Concanavalin A sepharose and can be eluted by an appropriate sugar such as α-methylmannoside, but not by an inappropriate sugar such as lactose. It was possible to undertake two sequential affinity chromatography steps—first absorption with picryl albumin sepharose and elution with picryl-ε-N-lysine followed immediately by absorption by Con A sepharose and elution with α-methylmannoside. The availability of sequential affinity chromatography provides a simple approach to the purification of specific T suppressor factor.