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KrosFlo® TFDF™ Lab System
User Guide
31
repligen.com IF.UG.023 R1
Sample and process information
Table 5. Sample and process
Parameter
Wizard
feature
requirement
Description
Percent Cell Volume (%PCV)
•
Values ~>20% may require extended diafiltration or
initial dilution of feed with buffer/media.
•
Maximum value ~35 - 40%
Starting Volume
•
Choose volume representative of scaled/scalable
process
Filter surface area
•
Choose size representative of scaled/scalable process
Cell Density
•
Minor impact on permeate quality when viability >
75%
•
Increasing significance with lower viabilities
Percent Viability
•
< 75% may increase permeate turbidity
•
< 75% may require increased diafiltration
Feed stock turbidity
•
Critical measurement for initial feed characteristic
•
Used to determine TFDF
™
turbidity reduction
Crossflow rate
•
Fixed value at 2L/min/fiber
Target yield
•
Typically 90 - 95%
•
Targeting higher yields may increase permeate
turbidity
•
Targeting higher yields may increase diafiltration
buffer requirement
Maximum final pool volume
•
Typically 110 - 120% of starting cell culture feed
volume
•
Increasing may increase yield with challenging samples
Initial concentration factor
•
Fold concentration of starting cell culture feed
•
Typically 2X when %PCV < 15%
•
Decreasing may improve yield or breakthrough with
challenging samples
Maximum time
•
Maximum allowed process time
•
Typically calculated by Wizard feature or automated
mode
Permeate Flux rate
•
650 LMH recommended standard value
•
Can be optimized based on specific feed
characteristics
•
> 650 LMH possible with high viability & low %PCV
Diafiltration buffer volume
•
Volume of diafiltration buffer wash in liters
•
Increasing volume may reduce fouling and increase
yield with challenging samples