Understanding the Options

Cell Culture Media Preparation:
Bacterial Retention Only

Prefiltration

(Not normally required for serum-free media)

Essential Process Requirements

• Protect sterilizing-grade filters by effectively removing lipids, colloids and particles without obstructing the flow of vital media constituents
• To ensure cost effectiveness and timely separation filters should have high flow rates and consistently high throughput
• Needs to work irrespective of variation from batch to batch
• Filter should have low extractables and low binding of key nutrients

Recommended Filter	Filter Characteristics
Triple-layer Millistak+ HC Filters (Grade A1HC) Disc Filters Pod Filters	Triple-layer configuration includes a membrane bottom layer to enhance filter loading capacity and retention Higher filtrate quality allows smaller size requirements for downstream sterilizing-grade filtration step Unique design enables the compression of multiple process steps into one, lowering overall filtration costs ALTERNATIVE: If media stream is less plugging, Millipore suggests testing single-layer Grade 75DE Millistak+ Filters in your small-scale trials.
Double-layer Polysep II Filters (Grade W3, 1.0 µm + 0.2 µm) Cartridge Filters Opticap Capsules Optiscale Capsules	Designed for the protection of downstream 0.1 µm sterilizing-grade filters Triple layer construction ensures high particle loading and capacity Robust construction ensures high particle loading and capacity Validated for multiple sanitization and SIP cycles Higher filtrate quality allows smaller size requirements for downstream sterilizing-grade filtration step Non-fiber releasing structure preserves product purity Cell growth studies confirm growth properties are preserved

Sterile Filtration

• Must remove bacteria
• Filter material must have low cytotoxicity, low extractables and low binding of key nutrients

Recommended Filter

Filter Characteristics

Millipore Express SHC 0.5 µm + 0.2 µm Filters Cartridge Filters Opticap Capsules Optiscale Capsules

Sterilizing-grade PES membrane with an additional PES prefilter layer all in one pleated device Designed for media additives and prefiltered tissue culture media in batch sizes ranging from 100 to 20,000 L Asymmetric pore structure delivers superior flow rates and capacity over a range of CHO and NS0 media PES membrane provides broad chemical compatibility across a wide pH range (1–14) 100% integrity tested to ensure quality Can be integrity tested on-site Robust construction validated for multiple SIP cycles ALTERNATIVE: If media stream is less plugging, Millipore suggests testing single-layer Grade 75DE Millistak+ Filters in your small-scale trials.