Understanding the Options

Plasma Fractionation - Clotting Factors

Clarification and Prefiltration

• Remove colloids, aggregated and non-product proteins, lipids and particles prior to downstream purification
• Protect downstream sterilizing-grade filters, chromatography media and TFF membranes
• Must be able to withstand multiple steam-in-place or hot water sanitization cycles
• Run efficiently to ensure process economics

Recommended Filter	Filter Characteristics
Single-layer Millistak+ DE Filters (Grade 65DE) Disc Filters Capsule Filters	Better suited for large volumes >500 L High internal surface area for maximum particle capture loading Graded density matrix enables retention of a wide range of particle sizes High porosity provides low pressure drop Although Grade 65DE is typical for this application, Millistak+ 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.
Double-layer Milligard Filters (Grade SC, 1.2 µm + 0.5 µm) Cartridge Filters Opticap Capsule Filters Optiscale Capsule Filters	Double-layer pleated configuration of mixed esters of cellulose membranes provide high dirt-holding capacity and retention efficiency High porosity membranes operate at high flow rates and low pressure drops Non-fiber releasing structure preserves product purity 100% integrity tested to ensure quality Robust construction validated to withstand multiple SIP or hot water sanitization cycles Grade SC is commonly used for this application; Milligard filters are available in numerous pore sizes and in single-layer or double-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.

Viral Clearance

• Critical step to ensure removal of viruses known to have contaminated source plasma such as parvovirus, hepatitis viruses and HIV
• Following current regulatory guidelines, 2 orthogonal methods are normally utilized to remove or inactivate viruses
• Validated log removal of viruses is a dedicated process step • Filtration products should easily scale-up and down for simple validation

Recommended Filter	Filter Characteristics
Viresolve NFR Filters	>6 log removal of retroviruses (80–120 nm) >98% recovery Utilizes size exclusion technology Robust PES membrane 100% integrity tested to ensure performance Can be integrity tested on-site
Viresolve NFP Filters	>4 log removal of parvoviruses and other small viruses >98% recovery of protein up to 160 kD Utilizes size exclusion technology Robust PVDF membrane 100% integrity tested to ensure performance Can be integrity tested on-site To enhance filter performance and capacity, Millipore suggests using the Viresolve Prefilter 18 series.

Ultrafiltration

• Reduce batch volumes and exchange buffer systems for efficient column operation and final formulation
• Run efficiently to ensure process economics

Recommended Filter

Filter Characteristics

Pellicon Cassettes with Biomax or Ultracel PLC Membranes

Low feed flow requirement minimizes pumping, working and hold up volumes Higher product recovery and flux Highly retentive void-free membranes offer good permeate flux and withstand process upsets Robust low binding Ultracel PLC void-free membranes provide excellent repeat performance For sera with caustic stability constraints Millipore suggests Biomax membranes. For low adsorption utilize Ultracel PLC membranes. Choose a membrane molecular weight cut-off 3–5X smaller than the biomolecule. Choice should be based on small-scale testing

Sterile Filtration

Essential Process Requirements

• Sterilizing-grade filters reduce bioburden and sterilize heat labile proteins
• Must be able to withstand multiple steam-in-place or hot water sanitization cycles
• Run efficiently to ensure process economics

Recommended Filter

Filter Characteristics

Durapore 0.22 µm Filters Cartridge Filters Optiseal Cartridge Filters Opticap Capsule Filters Optiseal Capsule Fitlers

Sterilizing-grade filters assure reduction of contaminating microorganisms that shorten the life of costly chromatography media Low-binding PVDF membrane assures protein yield 100% Integrity testing ensures quality 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 degree of protection required for the downstream process and the plugging characteristics of the fluid. Choice should be based on small-scale testing. Integrity testable on-site