Comparison of Results of Various Methods Used to Determine the Extent of Modification of Methoxy Polyethylene Glycol 5000-Modified Bovine Cupri-Zinc Superoxide Dismutase

New Polymer of lactic-co-glycolic acid-modified Polyethylenimine for Nucleic Acid Delivery

“…The yield of each new LGA-PEI polymer was determined by dry future science group New LGA-PEI polymer for nucleic acid delivery Research Article weight analysis. PEI amount and primary amine content were determined with the Cu(II) method [55] and the trinitrobenzene sulfonate assay, respectively [56].…”

“…The w/w ratios of PLGA to PEI ranged from 0.5:1 to 5:1, corresponding to molar ratios (n/n) that ranged from 1:1 to 10:1, respectively. For LGA-PEI (0.5:1 w/w) polymer, the PEI content in the polymer was 64.7.0 ± 1.6% according to the results of the copper sulfate assay [55], and the primary amine number was 49 ± 3% of that of PEI according to the trinitrobenzene sulfonate assay [56]. For LGA-PEI (1:1 w/w) polymer, the PEI content in the polymer was 48.0 ± 0.8%, and the primary amine number was 9.5 ± 2.1% of that of PEI.…”

PEGylation of magnetic poly(glycidyl methacrylate) microparticles for microfluidic bioassays

“…For example, conventional colorimetric (TNBS, fluorometric) 21,22 and chromatographic characterization (HPLC-SEC, RP-HPLC, gel permeation chromatography) [23][24][25] in combination with light scattering, MALDI-MS 24,[26][27][28] , and capillary electrophoresis 29,30 have been applied for analysis of PEGylated proteins. Specific colorimetric detection of PEG with iodine 31, 32 using Fourier transform infrared (FTIR) or Raman spectroscopy 24 and nuclear magnetic resonance 33, 34 have also been described. To monitor flat PEGylated surfaces, methods typically used include contact angle and zeta potential measurements, X-ray photoelectron spectroscopy (XPS), ellipsometry, as well as atomic force (AFM), scanning electron (SEM) and transmission electron (TEM) microscopy 16 .…”

Sodium dodecyl sulfate‐capillary gel electrophoresis of polyethylene glycolylated interferon alpha

“…However, the heterogeneity with respect to distribution in both the number and position of the attached PEG molecules and inherent polydispersity of PEG itself is still problematic [3,4]. Various methods have been used to characterize PEGylated proteins, but a considerable number of them failed to solve the problem of distinguishing individual PEG-protein conjugate [5]. CE has proved to be a powerful technique for the highresolution separation of biomolecules such as peptides and proteins [6].…”