For purification of other proteins from milk (which may involve same or similar steps) see Non-Antibody purification

For purificaiton of antibodies and other proteins from Inclusion bodies see outline

Separation of Immunoglobulins from Milk:

Particular Schemes:

–Filtration: 

—-MF-UF:

Doring (US14168586) discloses  a process for obtaining immunoglobuilins by subjecting colostral milk from days 0-7 to thermal treatment, skimming the cream and then subjecting the skimmed milk to microfiltration to obtain a first retentate and first permeate. The first permeate is then subjected to ultrafiltration to produce a seocnd permeate which contains lactose and minerals and a second retentate which contains the immunogloubilons, IgG1, IgA and IgM. The separation of the immunoglobuilins form the second retentate may then be performed according to processes known from the art such as through AEX. 

Hensgens (US 12/992701 and WO2009/139624) teaches a process for the preparation of an S-IgA enriched milk fraction by (a) separating fat from the milk at a temperature of below 55C, (b) separating the casein rich and S-IgA fraction by subjecting the low fat milk having a pH exceeding 5.5 to microfiltration using a porous membrane having an average pore size within a range of 0.1-0.45 micrometers where the casein is in the retentate and the S-IgA is contained in the permeate and (c) further concentration of the S-IgA by concentration as by UF.

Hobman (WO01/03515) discloses a method of purifying immunoglobuilin from colostrum (mammary secretion from a cow during the first 4 days postpartum) by taking a skim colsotrum stream and subjecteing it to MF to produce a permeate rich in colostral serum proteins and a serum deplete retentate enhacned with casein. In a preferred embodiment the permeate may be futher processed by US and/or DF the skim milk may be pasteurised for microbail hygiene prior to the MF. 

—-Cross-flow filtration:

Kothe (US 4644056) teaches a method of preparing immunoglobulins including secretory IgA by processing milk accompanied by preciptiation of the caseins characterized in that milk are acidified to a pH of 4.0-5.5, subjected to cross-flow filtration with a mean pore sieze of 0.1-1.2 um and the low molecular components removed by means of further cross-flow filtration.

Separation of Antibodies from Plants

While mammalian cell culture is the predominant expression system fo mAb production, yeilding mAbs with proper folding and glycosylation, the substantial resource requirements and viral clearance present challenges for this production system. Plant on the other hand offer a unique production platform for mAbs and have shown in recent years that they are able to express high levels of antibody. (Fulton, J Chromatogr A, 1389 128-132 (2015)

Particular Schemes:

DF- Charged polyelectrolyte preciption (+ charged to remove impurities) -Protein A/HIC:

(Fulton, J Chromatogr A, 1389 128-132 (2015) discloses a process of purification of a mAb against Ebola GP1 expressed in the plant N. benthmiana which includes a DF step and a charged polyelectrolyte precipitation. Polyethlenimine (PEI, a positively charged polyelectrolyte was used to precipitate acidic proteins and leave IgG in the supernatant.