Understanding the Options

Microbial Cell Culture Clarification
Inclusion Body (IB) Purification

Harvest/Clarification

• Recovery of Inclusion Bodies post cell lysis and before solubilization step
• Elimination of waste fluid in the filtrate
• High solids content in feed stream, which makes centrifugation a viable technology option
• Feed stream quality can vary depending on cell type and culture conditions

Recommended Filter

Filter Characteristics

TFF with Microfiltration Membrane Prostak Open-Channel Modules with 0.22 µm or 0.1 µm Durapore Membrane

Open-channel design accommodates high loading capacity and retention for haze removal post refolding High flux at low transmembrane pressure Robust construction allows multiple use Validated for multiple SIP cycles Selection of 0.22 µm or 0.1 µm membrane depends on particle size distribution in feed solution. Choice should be based upon small-scale testing. ALTERNATIVE: For small volumes with low cell densities,Pellicon V Screen Cassettes with 0.22 µm or 0.1 µm Durapore Membrane should be tested in your small-scale trials.

Sterile Filtration: Bioburden Reduction

• Reduces bioburden
• Protects downstream chromatography and UF/DF steps
• Maintains yield of dilute protein and preserves purity
• Sterilizing-grade filtration required

Recommended Filter	Filter Characteristics
Single-layer Durapore 0.22 µm PVDF Filters Cartridge Filters Optiseal Cartridge Filters Opticap Capsule Filters Optiseal Capsule Fitlers	Sterilizing-grade PVDF membrane won’t bind valuable protein 100% Integrity tested to ensure proven performance Can be integrity testable on-site Although 0.22 µm is typical for this application, Durapore filters are available in several pore sizes and, in single-layer or multi-layer configurations to accommodate the needs of each user, the degree of protection required for the downstream process and the plugging characteristics of the fluid. Choice should be based on small-scale testing.
Millipore Express SHC 0.5 µm + 0.2 µm PES Filters Cartridge Filters Opticap Capsules Optiscale Capsules	Sterilizing-grade PES membrane providing broad chemical compatibility across a wide pH range (1–14) Robust construction validated for multiple SIP cycles 100% integrity tested to ensure quality Asymmetric pore structure delivers extremely high flow rates at low pressure drop Can be integrity tested on-site Although double-layer 0.5 µm + 0.2 µm (SHC) is typical for this application, single-layer 0.2 µm (SHF) is also available. The degree of protection required for the downstream process and the plugging characteristics of the fluid will guide this selection. Choice should be based on small-scale testing.