6. Concentrate the “post-EtOH/CaCl 2 ” tenfold using TFF with
a 30-kDa molecular weight cut-off (MWCO), 200-cm
2
Hydrosart membrane. After concentration, perform diafiltration against 10 diavolumes of water (see Note 7). Collect the
retentate and indicate this solution as “TFF-2 retentate.”
7. Filter “TFF-2 retentate” through a 0.22 μm PES Nalgene
filter, indicate the solution as “post 0.22 μm” and store at 4
C.
Scheme 1 Flowchart of O-antigen purification process starting from the biomass
Fig. 2 Structure of S. paratyphi A O-antigen chain linked to the core region, after acetic acid hydrolysis
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a 30-kDa molecular weight cut-off (MWCO), 200-cm
2
Hydrosart membrane. After concentration, perform diafiltration against 10 diavolumes of water (see Note 7). Collect the
retentate and indicate this solution as “TFF-2 retentate.”
7. Filter “TFF-2 retentate” through a 0.22 μm PES Nalgene
filter, indicate the solution as “post 0.22 μm” and store at 4
C.
Scheme 1 Flowchart of O-antigen purification process starting from the biomass
Fig. 2 Structure of S. paratyphi A O-antigen chain linked to the core region, after acetic acid hydrolysis
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