Single-pass filtration systems and processes
The present invention provides, in various embodiments, hybrid single-pass tangential flow filtration assemblies, disposable single-pass tangential flow filtration assemblies, scalable single-pass tangential flow filtration assemblies and adaptable modular single-pass tangential flow filtration assemblies. In other embodiments, the invention relates to processes for recovering proteins from the surface of a filtration membrane in a single-pass tangential flow filtration assembly and for cleaning a tangential flow filtration assembly. In additional embodiments, the invention provides methods of increasing the processing capacity of a single-pass tangential flow filtration assembly.
1. A method of adding a processing unit to a single-pass tangential flow filtration (SPTFF) assembly, the method comprising:
a) establishing a fluid connection between a first processing unit in the SPTFF assembly and a second processing unit that is to be added to the SPTFF assembly, wherein the first and second processing units each comprise a cassette holder containing at least one TFF cassette and wherein the cassette holders of the first and second processing units are fluidly connected to each other by a first channel connected to a feed inlet, a second channel connected to a retentate outlet and a permeate channel, wherein the first channel, the second channel and the permeate channel in adjacent processing units are fluidly aligned, and wherein the first channel, second channel and permeate channel extend through the cassette holders of the first and second processing units; and
b) positioning a valve on the first channel between the first and second cassette holders of the processing units, and a spool piece or valve on the second channel between the first and second cassette holders, thereby preventing feed in the first channel in the first processing unit from flowing directly into the second processing unit when the valve on the first channel is closed and ensuring that the first and second processing units are processed in series.
2. A method of altering the processing capacity of the SPTFF assembly of claim 1 , the method comprising:
a) adding or removing at least one processing unit to or from the assembly;
b) replacing at least one TFF cassette in one or more processing units in the assembly with a TFF cassette having a different filtration membrane area;
c) adding or removing at least one TFF cassette to or from one or more processing units in the assembly; or
d) a combination thereof.
3. The method of claim 1 , wherein a valve is positioned on the first channel between the first and second cassette holders of the processing units.
4. The method of claim 1 , wherein at least one valve is positioned in the cassette holder.
5. The method of claim 1 , wherein at least one valve is separate from the cassette holder.