Impurity characterization can involve upstream buffer components, extractables, product carryover, product aggregates, bioburden and endotoxin.
Separation parameters such as injection time, buffer components, pH of the buffer were studied.
The samples of insulin and buffer components from Sigma (USA) were used without additional purification.
We also make the assumption that most buffer components do not affect the interaction that is being studied.
Finally, Fc fragments and buffer components were removed by extensive dialysis against PBS using a slide-a-lyzer cassette (Thermo scientific – Pierce) with a 10 kDa cut off.
Our data point towards two ways by which misfolded NTS1 may be generated: Damage by exposure to buffer components and by close contact of the receptor to the neurotensin affinity resin.
Chemicals and buffer components were purchased from Fischer, except monobromobimane, which was purchased from Molecular Probes.
HPLC solvents and buffer components were obtained from Sigma-Aldrich (St . Louis MO).
Tris buffer was used for these assays to minimize the background signal in the HPLC chromatograms that arose due to buffer components.
The exact threshold concentration may vary, depending on such factors as the type or make of DNA polymerase, primer sequences, amplicon, buffer components and cycling parameters.
(PBS buffer components used in this paper: 10 mM phosphate, pH 7.4, 138 mM NaCl, 2.7 mM KCl, and 2 mM MgCl2).
