HyperCel™ STAR AX Sorbent

Salt Tolerant Advanced Recovery Anion Exchange Chromatography Sorbent

Free SampleHyperCel STAR AX sorbent is an industry-scalable anion exchange chromatography sorbent designed for high productivity protein capture at moderate or higher salt conductivity (2 to 15 mS/cm), typical of undiluted biological feedstocks (i.e., mammalian cell culture supernatants, E. coli feedstock, plasma, others…).

Applications include direct capture of recombinant proteins, monoclonal and polyclonal antibodies, plasma derivatives or other biopharmaceuticals.

Due to its ability to capture directly proteins from undiluted feedstreams, HyperCel STAR AX sorbent can also be used for early contaminant removal (i.e., CHO Host Cell Proteins), before target purification, i.e., before MAb capture by a Protein A affinity step.

HyperCel STAR AX sorbent is manufactured at large scale and meets the needs of industrial users and regulatory authorities. A Regulatory Support File (RSF) is available to assist users in the development of validation procedures. This sorbent offers:

  • High dynamic binding capacity (DBC) at short residence time (2 minutes or lower)
  • Direct capture of protein from undiluted feedstock at moderate or high conductivity
  • Excellent flow rate properties for fast feedstock processing
  • Distinctive selectivity, consistent in a broad conductivity range (2 – 15 mS/cm)
  • Enhanced process economics

Features and Benefits

High Dynamic Binding Capacity in Broad Conductivity Operating Conditions: Avoids Feedstock Dilution and Streamlines Downstream Processing

Figure 2
Dynamic Binding Capacity vs. Residence Time as a Function of pH and Conductivity of HyperCel STAR AX Sorbent
Figure 2

Column: 0.5 cm I.D. x 5 cm bed height (∼1 mL). Sample: 5 mg/mL BSA in equilibration buffer. Equilibration buffer: 25 mM Tris-HCl, pH 7.0 – 8.5. Conductivity 3 – 20 mS/cm. Residence time: 1 – 4 min (0.25 – 1 mL/min). Numbers indicate binding capacity for BSA in mg/mL of sorbent.


A Design of Experiments study (DoE) was done to explore the influence of various pHs (7.0 to 8.5), conductivities (3 to 20 mS/cm) and residence times (1 to 4 minutes) on the dynamic binding capacity for bovine serum albumin (BSA) used as a model.

Data shows the impact of pH and conductivity on DBC for BSA on HyperCel STAR AX sorbent. The contour plots in Figure 2 show that the sorbent achieves a high DBC (> 100 mg/mL) over a wide range of pHs and conductivities at short residence time, allowing optimal process flexibility and productivity.

Figure 3

Dynamic Binding Capacity of HyperCel STAR AX Sorbent for Human Serum Albumin (HSA) from Undiluted and Diluted Plasma
Figure 3 

Figure 3 shows the DBC for HSA of HyperCel STAR AX sorbent compared to a conventional rigid agarose DEAE anion exchange sorbent at conductivities corresponding to undiluted (11 mS/cm) and diluted (7 mS/cm) plasma.

Data shown in Figure 3 confirms that DBC is less affected by conductivity in the 7 – 11 mS/cm range, compared to conventional sorbent. This allows direct load of undiluted plasma on HyperCel STAR AX sorbent.

Combined with excellent flow characteristics at low backpressures (Figure 1), large volumes of feedstock can be processed directly and fast, increasing the overall process throughput, and limiting the risk of protein degradation.

High binding capacity facilitates operation using columns of moderate volume and footprint, allowing further reduction in buffer-volume requirements, and leading to equipment savings and reduced investment costs for sorbents.

Excellent Selectivity and Separation Efficiency over a Broad Range of Conductivities

Figure 4 Separation of a Protein Mix on HyperCel STAR AX Sorbent at 10 mS/cm.
Figure 4

HyperCel STAR AX PRC prepacked column of 1 mL; 100 µL mix (2 mg/mL cytochrome C, 10 mg/mL human transferrin, 10 mg/mL bovine serum albumin [BSA]). Load: 25 mM Tris-HCl pH 8.0, 10 mS/cm. Elute: gradient 0 – 50% 25 mM Tris-HCl, pH 8.0 + 1 M NaCl.

Sorbent selectivity is a key parameter to discriminate between the target protein and contaminants in the feedstock. Screening of sorbent selectivity is critical and should be done at early stages of process development.

Rapid screening and condition optimization can be achieved using a Pall 1 mL PRC prepacked column. Once the appropriate chemistry is selected, the conditions of use can be optimized in a 5 mL PRC column by doubling the height. Two 5 mL columns can be connected in series to increase the column bed height to 20 cm, and more closely model real conditions in pilot scale or for scale-down applications. Columns of 1 mL can also be connected in series.

Due to the difference in the bead structure, ligand chemistry and the specific ionic charge density, as shown in Figure 4, the selectivity and separation efficiency of HyperCel STAR AX sorbent is maintained in a broad range of conductivities.