b'Storage conditions for antibodies and antibodyenzyme conjugates Antibody solutions for western blotting are typically dilutedEthylene glycolfrom 1:100 to 1:500,000 beginning from a 1 mg/mL stockThermo Scientific Ethylene Glycol provides exceptional solution. These 1 mg/mL stocks often can be stored atantifreeze protection and storage stability for antibody4C for days to weeks without significant loss in activity.enzyme conjugates because it is purified to remove However, for increased stability, glycerol or ethylene glycolimpurities commonly found in traditional glycerol stocks. may be added to a final concentration of 50% and theThe 50% (w/v) aqueous solution, when mixed in equal antibody can be stored at 20C. Alternatively, the antibodyvolumes with purified protein samples such as primary solution may be stored in small working aliquots at 20Cantibodies, stabilizes and maintains the mixture as a liquid to avoid repeated freeze/thaw cycles. Antimicrobial agentsduring freezer storage (20C).such as sodium azide or thimerosal may be added to avoid microbial growth.Features: Specially purified to remove impurities such as Generally, antibody conjugates are best stored ataldehydes, peroxides, iron, and UV-absorbing 20C with glycerol or ethylene glycol added at a finalhydrocarbonsconcentration of 50%. Although some enzyme conjugates may be stored at 20C without cryoprotectant, frozen Suitable for enzyme storage without the worry of losing stocks must be as single-use aliquots to prevent repeatedenzymatic activityfreeze/thaw cycles; AP conjugates are particularly sensitive Stable for monthsto freezing. Conjugates typically maintain good activity for 12 years if stored at 20C with glycerol or ethylene glycol. However, contaminants in cryoprotectants may affect enzyme activity, and few researchers take steps to ensure the purity of the cryoprotectant used. For both unlabeled and labeled antibodies, it is best to refer to the manufacturers recommendations for specific storage conditions.39'