- Protein G Conjugation to CMRD-SPIO
- The following protocol is used in conjunction with the CMRD-SPIO protocol
- Change the CMRD-SPIO buffer to 100mM HEPES pH 4.7
- Spin down 1mL CMRD-SPIO against 2 500 ul 100 kDa MWCO membrane at 7000 rpm for 5 min
- Add 500 ul 100 mM HEPES pH 4.7 to each tube of CMRD-SPIO, pipet up and down a few times to mix, and spin down at 7000 rpm for 5 min
- Add a second round of 500 ul 100 mM HEPES and spin down again.
- Transfer CMRD-SPIO to an Eppendorf flip tube and add 5 mg each of NHS and EDC
- Incubate for 2 hrs at room temperature or overnight at 4oC
- After incubation, purify CMRD-SPIO on Spehadex G25 column with 1x PBS pH 7.4
- Desired eluent will be easy to spot as the CMRD-SPIO is dark brown
- Concentrate the eluent against a 15 mL 5 kDa MWCO membrane at 2500 rpm for 30 min
- Add 1 mg/ml of Protein G to CMRD-SPIO solution and incubate at 4oC overnight
- Purify CMRD-SPIO on Spehadex G25 column with 1x PBS pH 7.4
- Concentrate eluent against a 15 mL 5 kDa MWCO membrane at 2500 rpm for 30 min
- Add desired antibody in concentration of 20 ug/ml and incubate at 4oC overnight
- Purify CMRD-SPIO against using a Sephadex G200 column to remove unbound antibody
- Store at 4oC
Edited By Mitchell Weiser 3/16/07