Millistak+HC AppGd_textC.qxd - Millipore

Understanding
Millistak+ HC High
Performance Stacked Filters
Millistak+ HC filters are a unique
clarification/prefiltration tool
developed to meet the critical needs
of the biopharmaceutical industry.
Designed expressly for large-scale
mammalian cell fermentation
processes, Millistak+ HC filters
combine multiple clarification steps
into a single unit operation.
Innovative Dual-Action Filter
The technology is built upon the
superior performance qualities of
the cellulosic filter media available
in the Millistak+ filter product line.
The DE Series filter media consists of
refined cellulose fibers and high-purity
diatomaceous earth. The composite
is chemically treated to impart a
cationic (positive) surface charge,
to enable the capture of negativelycharged
biological particulates and
colloids (cell fragments, protein
agglomerates, etc.).
Millistak+ HC filters represent the
next generation of the stacked-disk,
cellulosic depth filter. The principal
design feature of Millistak+ HC filters
is a graded pore structure, tailored to
maximize the holding capacity of the
filter for the broad range of particle
sizes typical of fermentation fluids.
Two full-thickness cellulosic pads
are employed—a fine grade media
overlaid by a coarser grade—which
together span a far wider range of
pore size than achievable in any
single-grade filter. For particular
configurations of Millistak+ HC filters,
the construction is further enhanced by
the addition of a microporous cellulose
membrane underlying the dual-layer
depth filter media, to further extend
small particle retention.
Millistak+ HC Filter
Open DE Grade
Tighter DE Grade
Cellulosic Membrane
For process-scale operations,
Millistak+ HC filters are available
as a lenticular, stacked-disk cartridge
containing eight double-sided, 16-inch
diameter disks for 1.8 m 2 frontal
Millistak+ HC Filters Application Guide 1
Flow
Figure 1. Media Layers of Millistak+ HC
Filters