Analysis of PEG-conjugates

Table 2.5 Molecular weight analysis of PEG-CV-N conjugates using linear PEG standards (in Da)...

FIG. 10 XPS analysis of anchoring PEG-DEX conjugates into the surfaces of PLG microparticles. The top Cls data was recorded from a PLG control sample and displays considerable hydrocarbon contamination. The bottom Cls region proves the presence of the PEG-DEX conjugate at the microparticle surface due to the presence of a significant C-Opi> peak. (From Ref. 38.)... 

An accurate determination of molecular weight can be done by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) analysis. Fig. 2.7 demonstrates the effect of polydispersity on the MALDI-TOF analysis of mPEG 5-kDa MAL CV-N. Each peak is separated by 44 mass units associated with the ethyleneoxy units of the polymer. The polydispersity increases with an increase in the size of the PEG. The PEG-conjugate is also polydis-perse and the resolution of the peaks decreases as the molecular weight of either the PEG or the protein increases. The pro-... 

Figure 18 Gamma-distribution of the PIC micelle composed of an acetal-PEG-ODN conjugate and L-PEI at iV/P= 1 obtained from a histogram analysis of DLS (detection angle, 90° temperature, 37°C).

Multilayers of alternating goat anti-mouse and mouse anti-goat IgG were built by stepwise immobilization of both antibodies on a glassy carbon electrode. The labeled IgG conjugates were immobilized on top of these molecular layers of variable thickness. Quantitative analysis of the dynamics of the redox probe grafted to the self-assembled construction via the linear and flexible PEG chain was extracted from cyclic voltammetric measurements [43]. 

Fig. 7 Use of PEG - Met - Nle - OSu or PEG-Met- SAla-OSu to introduce a reporter amino acid at the PEGylation site PEG conjugation followed by polymer moiety release by BrCN leaves Nle or )0Ala, which can be identified on the protein by amino acid sequence analysis...

Fig. 8 SDS-PAGE analysis of the PEGylated interferon Qf-2a mixture. The conjugates were A specifically stained for protein with Coomassie blue—lane 1 molecular weight marker proteins lane 2 PEGylation reaction mixture lane 3 purified PEG2-IFN and lane 4 interferon-2 a. B Specifically stained for PEG with iodine—lane 1 molecular weight marker PEGs lanes 2-4 same as in Fig. 2A. Note that lane 4, containing interferon a-2a in gel B, is not stained by iodine, reproduced from [19]...

Nellis DF et al (2005) PrecKnical manufacture of anti-HER2 liposome-inserting, scFv-PEG-Hpid conjugate. 2. Conjugate micelle identity, purity, stability, and potency analysis. Biotechnol Prog 21 221-232... 

The stability of ODN against nuclease is an important issue for in vivo application. Both the acetal-PEG-ODN conjugate and its PIC micelle with L-PEI were incubated with deoxyribonuclease (DNase I) for appropriate time intervals (5, 30, 60, and 120 min), and the digestion of ODN was quantified by means of an SEC analysis. So that an exact evaluation of the stability against DNase I attack of ODN in PIC micelles could be obtained, excess dextran sulfate (counter polyanion) was added to the PIC micelles solution. This step... 

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