Spectra polyacrylamide

There are many examples of ELIS As used for detecting host cell impurities in the literature. Pauly et al.12 developed an ELISA to detect impurities in erythropoietin that had a detection limit of around 0.05 ng/ml. SDS polyacrylamide gel and Western blot analysis were used to confirm the spectrum of proteins detected and to demonstrate the specificity of the antibody preparation. Anicetti et al.14 describe an assay for the detection of E. coli proteins in recombinant DNA-derived human growth hormone. Whitmire and Eaton15 report on an immuno-ligand assay for quantitation of process-specific E. coli host cell contaminant proteins in a recombinant bovine somatotropin. 

SBA, prepared as described herein, possessed an ultraviolet (UV) absorption spectrum and an extinction coefficient comparable to those previously reported (5). Polyacrylamide gel electrophoresis in the presence of SDS resolved SBA into two closely spaced peptide bands comparable to those reported by Lotan et al. (6). ... 

Such polyacrylamide type CSPs are best operated under normal-phase conditions (usually u-hexane with a polar modifier like alcohols, dioxane, THF, etc.). The spectrum of applicability includes a wide variety of drug substances with hydrogen donor-acceptor and aromatic groups. Other groups also prepared CSPs from chiral (meth)acrylamide monomers with various chiral amino components. An extensive review on this topic was published by Kinkel 47j. 

The visible absorption spectrum of a solution containing a known concentration of nitrated protein is measured in a solution buffered at pH 9.0, and the absorbance at the maximum (near 428 nm) used to calculate the nitrotyrosine content ( 428nm for the nitrophenoxide ion is 4200). The tyrosine and nitrotyrosine content of the modified protein should also be determined by amino acid analysis. If the sum of these values does not add up to the tyrosine content of the unmodified protein, intra- or intermolecular cross-linking may have occurred. The amino acid analysis may also reveal whether other side-reactions have taken place. Particular attention should be paid to the half-cystine, cysteine, methionine, histidine and tryptophan contents of the modified proteins. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate offers a rapid and highly sensitive way of detecting products of intermolecular cross-linking. Such products are readily removed by gel filtration. 

In this paper the solution properties of a spectrum of mobility control polymers have been compared. Polysaccharides, polyacrylamides, and hydroxy ethyl cellulose show vastly different solution behavior. Despite this, the properties investigated can be correlated by noting one molecular characteristic of these polymers, namely molecular size. 

Figure 7a. ESC A C Is spectrum of the luminal surface of polyacrylamide-Silastic tubing in the dehydrated state.

Figure 9. ESC A spectra of pure polyacrylamide film cast on glass. Key a, C 1 s spectrum resolved (using a DuPont 310 analog curve resolver) into its component peaks and b, N 1 s spectrum.

Methylumbelliferone (4-MU) incorporated in polyacrylamide capsules permeable to protons was the earliest fluorophore investigated for intravascular fluorimetric measurements [45]. The emission spectrum displays an isosbestic wavelength at 330 nm, and the dissociated form has its peak at 365 nm. The ratio of the measured intensities is related to the pH. The response time is less than 2 minutes. This pH measurement (range 6.5-8.5) is advantageously taken with determination of the ionic strength [46] in combination with 1-hydroxypyrene-3,6,8-trisulfonic acid (HPTS) [47] (see Section 17.1.1.3). 

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