Phycobiliproteins activation with SPDP

Conjugates of avidin or streptavidin with these fluorescent probes may be prepared by activation of the phycobiliprotein with SPDP to create a sulfhydryl-reactive derivative, followed by modification of avidin or streptavidin with 2-iminothiolane or SATA (Chapter 1, Section 4.1) to create the free sulfhydryl groups necessary for conjugation. The protocol for SATA modification of avidin or streptavidin can be found in Section... 

The SPDP-activated phycobiliprotein may be reacted with a sulfhydryl-containing protein to create a fluorescent conjugate linked through disulfide bonds. 

The procedure for SPDP activation of phycobiliproteins can be found in Chapter 8, Section 1.7. Reacting the SPDP-activated phycobiliprotein with SH-labeled avidin at a molar ratio of 2 1 will result in highly fluorescent biotin-binding probes. 

---