Novel Displacement Agents for Aqueous 2-Phase Extraction Can Be Estimated Based on Hybrid Shortcut Calculations

Influence of Sodium Chloride and Lithium Bromide on the Phase Behavior of a Citrate–Polyethylene Glycol 2000 Aqueous Two-Phase System

“…The results on the influence of NaCl for the (NH 4 ) 3 Cit–PEG2000 ATPS and K 3 Cit–PEG2000 ATPS are in agreement with previous investigations by Kress et al (2016) for Na 3 Cit–PEG2000 ATPS and two other groups. ,, All results indicate that the addition of NaCl leads to an increase of the PEG amount/fraction in the top phase at constant TLS but increasing TLL and thus decreasing H 2 O ratio . As for the Na 3 Cit–PEG2000 ATPS, the biphasic region of the (NH 4 ) 3 Cit–PEG2000 (Figure a) and K 3 Cit–PEG2000 ATPS (Figure b) is thus increased.…”

“…Within ATPE, the partitioning of the target molecules is dictated by the selection of appropriate phase formers that create the respective ATPS . In order to tune the partitioning, a displacement agent, mostly a neutral salt, is often added to selectively displace the target biomolecule into the preferred phase while it is desired that the contaminants remain in the other phase (depending on their physio-chemical properties). ,,− Several groups investigated the influence of sodium chloride (NaCl) on salt-polyethylene glycol (PEG) ATPS and showed that a selective partitioning of the target biomolecule Immunoglobulin G (IgG) into the PEG-rich phase was possible, obtaining a yield of higher than 98.5%. , Besides NaCl, Kress et al (2016) investigated the influence of lithium bromide (LiBr) as a new displacement agent added to trisodium 2-hydroxypropane-1,2,3-tricarboxylate (trisodium citrate, (Na 3 Cit))–PEG2000 ATPS . LiBr allows for selective separation of IgG from the contamination human serum albumin (identified as a representative impurity) within Na 3 Cit–PEG2000 ATPS with an IgG yield of 74.6% …”

“…Although used in almost every ATPE application published, systematic experimental investigations on the influence of displacement agents (e.g., neutral salts such as NaCl and LiBr) on the phase behavior of the ATPS are very scarce. ,− Within this work, the influence of the displacement agents NaCl and LiBr on the phase composition/phase behavior of triazanium 2-hydroxypropane-1,2,3-tricarboxylate [triammonium citrate, ((NH 4 ) 3 Cit)]–PEG2000 ATPS and tripotassium 2-hydroxypropane-1,2,3-tricarboxylate [tripotassium citrate, (K 3 Cit)]–PEG2000 ATPS was investigated at pH 7, 298.15 K, and 101.3 kPa. Both “base” ATPSs [((NH 4 ) 3 Cit)–PEG2000 and K 3 Cit-PEG2000] were already reported in literature, , although the influence of an additional displacement agent was not considered, and they are regarded suitable for ATPE of biomolecules.…”

“…Both “base” ATPSs [((NH 4 ) 3 Cit)–PEG2000 and K 3 Cit-PEG2000] were already reported in literature, , although the influence of an additional displacement agent was not considered, and they are regarded suitable for ATPE of biomolecules. The influence of NaCl and LiBr on the phase behavior of the (NH 4 ) 3 Cit–PEG2000 ATPS and K 3 Cit–PEG2000 ATPS is compared to the influence of the same displacement agents on the previously investigated Na 3 Cit–PEG2000 ATPS . Therefore, the same conditions as applied by Kress et al (2016) were chosen within this work.…”

Sedimentation velocity analytical ultracentrifugation for characterization of therapeutic antibodies

“…Composition gradient static light scattering (CG-SLS) is another approach to investigate self-and hetero-associations of proteins at high concentration (Attri and Minton 2005). By using CG-SLS, the second virial coefficient of the IgG-IgG interaction was determined over the range of concentrations up to >150 mg/mL (Kress et al 2016), allowing assessment of the extent of intermolecular interactions and thus being a useful tool for the rational formulation development (Saito and Uchiyama 2016).…”