# US 11,028,124 B2 · Methods, devices and systems for 3-stage filtration

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,028,124 B2
- Document ID: US11028124B2
- Status: Granted
- Kind: B2
- Application number: 15/972,442
- Filed: 2018-05-07
- Published: 2019-11-07
- Granted: 2021-06-08
- Earliest claimed: 2018-05-07
- Assignees: Repligen Corporation
- Applicants: Repligen Corporation
- Inventors: Michael Bransby
- Web page: https://patentgrep.com/patent/US11028124B2

## CPC

- B01D 61/147: {Microfiltration}
- C07K 1/36: by a combination of two or more processes of different types
- B01D 15/3809: {of the antigen-antibody type, e.g. protein A, G or L chromatography}
- B01D 61/149: {Multistep processes comprising different kinds of membrane processes selected from ultrafiltration or microfiltration}
- B01D 63/02: Hollow fibre modules
- B01D 69/08: Hollow fibre membranes (manufacture of hollow fibres D01D5/24, D01F1/08)
- C07K 1/22: Affinity chromatography or related techniques based upon selective absorption processes
- C07K 1/34: by filtration, ultrafiltration or reverse osmosis
- C12M 47/04: {Cell isolation or sorting (purging biological preparations of unwanted cells C12N5/0081, determining the presence or kind of microorganism C12Q1/04)}
- C12M 47/10: {Separation or concentration of fermentation products (bioreactors combined with means for distillation or extraction of liquid fuel C12M43/02)}
- B01D 2311/06: Specific process operations in the permeate stream
- B01D 2311/2626: Absorption or adsorption
- B01D 2315/10: Cross-flow filtration
- B01D 2315/14: Batch-systems
- B01D 2317/022: Reject series
- B01D 2317/025: Permeate series
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)
- C12M: APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; {APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS}

## Abstract

The present disclosure pertains to filtration methods comprising: passing a first fluid that comprises cells, cell debris and targeted product produced by the cells through a first filter thereby separating the first fluid into a first retentate comprising cells and a first permeate comprising targeted product and cell debris; combining resin beads having affinity for targeted product with the first permeate to form a second fluid containing resin beads with bound target product and cell debris; passing the second fluid through a second filter thereby separating the second fluid into a second retentate comprising resin beads with bound target product and a second permeate comprising cell debris; combining an elution buffer with the second retentate to form a third fluid that comprises a mixture of resin beads and unbound targeted product; and passing the third fluid through a third filter thereby separating resin beads from targeted product.

## Claims

### Claim 1

A filtration method comprising:
passing a first fluid that comprises cells, cell debris and a targeted product produced by the cells through a first filter such that the first fluid is separated by the first filter into a first retentate comprising the cells and a first permeate comprising the targeted product and a first portion of the cell debris that passes through the first filter;
combining resin beads having affinity for the targeted product with the first permeate such that a second fluid is formed that comprises the resin beads with bound target product and the first portion of the cell debris;
passing the second fluid through a second filter such that the second fluid is separated by the second filter into a second retentate comprising the resin beads with the bound target product and second permeate comprising a second portion of the cell debris that passes through the second filter;
unbinding the targeted product from the resin beads with the bound targeted product such that a third fluid is formed that comprises a mixture of the resin beads and the targeted product; and
passing the third fluid through a third filter such that the third fluid is separated by the third filter into a third retentate comprising the resin beads and a third permeate comprising the targeted product.

### Claim 2 (depends on 1)

The method of claim 1, further comprising combining an elution buffer with the second retentate such that the targeted product becomes unbound from the resin beads with the bound targeted product to form the third fluid.

### Claim 3 (depends on 2)

The method of claim 2, wherein the second retentate is directly combined with the elution buffer.

### Claim 4 (depends on 3)

The method of claim 3, further comprising washing the second retentate by a process wherein the second retentate is mixed with a washing solution and subjected to additional filtration to further reduce the amount of cell debris in the second retentate before combining with the elution buffer.

### Claim 5 (depends on 1)

The method of claim 1, wherein the filtration method is a batch process.

### Claim 6 (depends on 5)

The method of claim 5, wherein the resin beads and the first permeate are combined in a first batch mixer, wherein an elution buffer and the second retentate are combined in a second batch mixer, or both.

### Claim 7 (depends on 1)

The method of claim 1, wherein the filtration method is a continuous process.

### Claim 8 (depends on 7)

The method of claim 7, wherein the second fluid is passed through a first static mixer prior to passage through the second filter, wherein the third fluid is passed through a second static mixer prior to passage through the third filter, or both.

### Claim 9 (depends on 1)

The method of claim 1, further comprising regenerating the resin beads in the third retentate.

### Claim 10 (depends on 1)

The method of claim 1, wherein the targeted product is a protein.

### Claim 11 (depends on 1)

The method of claim 1, wherein the targeted product is a monoclonal antibody or a polyclonal antibody.

### Claim 12 (depends on 1)

The method of claim 1, wherein the resin beads are functionalized with one or more ligands selected from Protein A, Protein G, Protein A/G, and Protein L.

### Claim 13 (depends on 1)

The method of claim 1, wherein the first filter has a mean pore size ranging from 1 μm to 8 μm.

### Claim 14 (depends on 1)

The method of claim 1, wherein the first filter is a first tangential flow filter.

### Claim 15 (depends on 14)

The method of claim 14, wherein the first tangential flow filter comprises hollow fibers having an inner lumen diameter ranging from 1 mm to 7 mm and a wall thickness of 1 mm to 8 mm.

### Claim 16 (depends on 1)

The method of claim 1, wherein the second filter has a mean pore size ranging from 2 μm to 30 μm.

### Claim 17 (depends on 1)

The method of claim 1, wherein the second filter is a second tangential flow filter.

### Claim 18 (depends on 17)

The method of claim 17, wherein the second tangential flow filter comprises hollow fibers having an inner lumen diameter ranging from 1 mm to 7 mm and a wall thickness of 1 mm to 8 mm.

### Claim 19 (depends on 1)

The method of claim 1, wherein the third filter has a mean pore size ranging from 2 μm to 30 μm.

### Claim 20 (depends on 1)

The method of claim 1, wherein the third filter is a third tangential flow filter.

### Claim 21 (depends on 20)

The method of claim 20, wherein the third tangential flow filter comprises hollow fibers having an inner lumen diameter ranging from 1 mm to 7 mm and a wall thickness of 1 mm to 8 mm.