1. Nâ-cystaminebisacrylamide (CBA) + ABOL in methanol / water (4/1) at 45° C for six days.
2. Add EDA and 45 oC for two days.
3. Add excess of EDA.
4. Purify by ultrafiltration (MWCO 1000, pH 5).
5. Filter through a 0.45 ÎŒm filter, recover by lyophilization.