The importance of immunoglobulin Y (IgY) as a specific antibody equivalent to mammalian immunoglobulin G (IgG) is well recognized. However, production of highly purified IgY is still difficult due to the lack of specific purification methods. In this study, adsorption behaviors of IgY on four mixed-mode resins with functional ligands of 4-mercatoethyl-pyridine (MEP), 2-mercapto-1-methyli-midazole (MMI), 5-aminobenzi-midazole (ABI) and tryptophan-5-aminobenzi-midazole (W-ABI) were evaluated. The results showed that high adsorption ratio were found at pH 6.0–7.0 with little adsorption under acidic conditions. The resin with ABI ligand was then used to separate IgY from immunized chicken serum. An efficient process with IgY purity of 95% and recovery of 90% was developed after optimization of loading and elution pH and injection volume. The biological activity of the purified IgY was fully maintained. These results indicated that mixed-mode chromatography with specially-designed ligands has great potential for the separation of IgY from crude feedstock.
Jia Ding,Lanlan Gao,Lulu Cao,Yunlei Zhou,Hao Wang,Jingrui Duan,Huanshun Yin,Jianchao Sun,Shiyun Ai
DNA hydroxymethylation is an important epigenetic modification, which plays crucial roles in many biological processes, such as gene expression and cell differentiation. Herein, a novel photoelectrochemical immunosensor was built for detecting 5-hydroxymethylcytosine (5hmC), where the perovskite Bi 4 TaO 8 Cl sensitized by 3,4,9,10-perylenetetracarboxylicacid (PTCA) was implemented as photoactive material, anti-5hmC antibody was served as target recognition reagent, ZrO 2 was used for connecting more modifications, and ferrocene was adopted as signal amplification unit. The prepared nanomaterials of Bi 4 TaO 8 Cl, PTCA and ZrO 2 were well characterized. The possible mechanism for the improved PEC response of Bi 4 TaO 8 Cl sensitized by PTCA was investigated carefully, indicated that the matched energy band facilitated the migration of photogenerated electron. In addition, the possible mechanism for signal amplification caused by ferrocene was investigated, showing that ferrocene acted as electron donor to accelerate electron transfer. Under the optimal condition, the biosensor manifested wide detection range from 0.02 to 100 nM with the low detection limit of 5.2 pM (S/N = 3). Moreover, the applicability of the biosensor was demonstrated by investigating the effect of heavy metal Cd 2+ and perfluorooctanoic acid on 5hmC content in the leaves and roots of wheat seedlings, as well as the effect of ALV-J on 5hmC content in chicken serum.