GFP | Green Fluorescence Protein (affinity purified)

Highly purified native GFP protein derived from Aequorea victoria, UniProt: P42212

western blot 



Protein extracts were obtained from Arabidopsis thaliana seeds (producing atLEA4-5 fused to GFP; other lanes contain GFP-6H loaded in indicated amounts). Following extraction buffer was used: 0.7 M sucrose, 0.5 M Tris-base, 30 mM HCl, 50 mM EDTA, 0.1 M KCl, 2% β-mercaptoethanol, 12 mg/ml poly-vinyl-poly-pyrrolidone (PVPP). This buffer was complemented with 2mL of equilbrated phenol before extraction. Samples were centrifuged and the protein phase was recovered; the extracted proteins were precipitated with 0.1 m ammonium acetate dissolved in methanol, centrifuged and the pellet washed with cold (-20 ℃) 80% acetone. The protein pellet was dissolved in SDS-solubilization buffer (1% CHES, 2% SDS, 2% ß-mercaptoethanol, 10% glicerol). Thirty 𝜇g of seed protein extract was denatured with Laemmli buffer at 95 °C for 5 min and proteins were separated on 15% SDS-PAGE and blotted 1.5 h to nitrocellulose membrane in a liquid transfer system. Blots were blocked with 2% skim milk ON at 4°C with agitation. After rinsing with TBS, blots were incubated in the primary antibody at a dilution of 1:10 000 (anti-GFP) for 3h at 4°C with agitation. The antibody solution was decanted and the blot was rinsed briefly, then washed once for 15 min. and 3 times for 5 min in TBS-T at 4°C with agitation. Then, blots were incubated in secondary antibody (anti-rabbit IgG horse-radish peroxidase conjugate) diluted to 1:25 000 in for 1h at RT with agitation. The blot was washed as above and developed for 2 min with SuperSignal West Pico Chemiluminescent Substrate, Thermo Fisher Scientific. Exposure time was for 30 seconds.

Courtesy of Dr. Alejandra Covarrubias, UNAM, Mexico

Minimal cross-reactivity with E.coli proteins.

GFP (Green fluorescent protein) was originally identified in photo organs on jellyfish Aequorea victoria. It is a naturally fluorescent protein which emits green light at a maximum wavelength of 509 nm when excited by blue or UV light. It is extensively used in laboratory as a reporter molecule to label and study cellular and subcellular proteins in living cells using a wide range of applications. Antibodies to GFP protein are used in immunoblotting and ELISA. GFP protein has molecular weight of 27 kDa.