Cho host cell protein assay

Abstract

The present invention provides compositions, kits, and methods for the detection of host cell proteins (HCPs) in biological samples. In some embodiments, the present invention utilizes immunization of ayes hosts with proteins derived from non-ayes host cells to produce ayes antibodies specific for non-ayes HCPs.

1 . A method of isolating a plurality of antibodies from an egg yolk comprising:
 (a) separating the egg yolk from albumen to form an egg yolk solution;   (b) lowering the pH of the egg yolk solution to pH 5.0±0.2;   (c) incubating the egg yolk solution to form a liquid portion of the egg yolk solution;   (d) collecting the liquid portion and centrifuging the liquid portion;   (e) removing a first supernatant from the centrifuged liquid portion and centrifuging the first supernatant;   (f) removing a second supernatant from the centrifuged first supernatant and adjusting the pH of the second supernatant to pH 7.0±0.2 to form a neutralized supernatant; and   (g) concentrating the neutralized supernatant,   wherein the neutralized supernatant comprises the plurality of antibodies.   
     
     
         2 . The method of  claim 1 , wherein the lowering of the pH in step (b) comprises lowering the pH using HCl. 
     
     
         3 . The method of  claim 1 , wherein the incubating in step (c) is overnight at 4° C. 
     
     
         4 . The method of  claim 1 , wherein the adjusting of the pH of the second supernatant in step (0 comprises adjusting the pH using NaOH. 
     
     
         5 . The method of  claim 1 , wherein the plurality of antibodies are IgY antibodies. 
     
     
         6 . The method of  claim 1 , wherein the egg yolk is obtained from an ayes host. 
     
     
         7 . The method of  claim 6 , wherein the ayes host is selected from the group consisting of ducks, geese, swans, turkeys, guinea fowl, squabs, pigeons, pheasants, quails, and chickens. 
     
     
         8 . The method of  claim 7 , wherein the ayes host is a chicken. 
     
     
         9 . The method of  claim 6 , wherein the ayes host is immunized with host cell proteins (HCPs). 
     
     
         10 . The method of  claim 6 , wherein the ayes host is immunized with antigens derived from mammals, insects, yeast or bacteria. 
     
     
         11 . The method of  claim 10 , wherein the ayes host is immunized with antigens derived from bacteria. 
     
     
         12 . The method of  claim 10 , wherein the plurality of antibodies are specific for the antigens derived from mammals, insects, yeast or bacteria. 
     
     
         14 . The method of  claim 1 , wherein the concentrating neutralized supernatant comprises dialysis or filtration. 
     
     
         15 . The method of  claim 1 , further comprising purifying the plurality of antibodies from the neutralized supernatant. 
     
     
         16 . The method of  claim 15 , wherein the purifying is by gel filtration, anion exchange, and/or affinity chromatography. 
     
     
         17 . The method of  claim 1 , wherein the centrifuging in steps (e) and (f) is at 10,000 rpm for 10 minutes at 4° C. 
     
     
         18 . A method of isolating a plurality of IgY antibodies from a chicken egg yolk comprising:
 (a) separating the chicken egg yolk from albumen to form a chicken egg yolk solution;   (b) lowering the pH of the chicken egg yolk solution to pH 5.0±0.2;   (c) incubating the chicken egg yolk solution to form a liquid portion of the chicken egg yolk solution;   (d) collecting the liquid portion of the chicken egg yolk solution and centrifuging the liquid portion;   (e) removing a first supernatant from the centrifuged liquid portion and centrifuging the first supernatant;   (f) removing a second supernatant from the centrifuged first supernatant and the adjusting the pH of the second supernatant to 7.0±0.2 to form a neutralized supernatant; and   (g) concentrating the neutralized supernatant,   wherein the neutralized supernatant comprises the plurality of IgY antibodies.   
     
     
         19 . The method of  claim 18 , wherein the chicken egg yolk is from a chicken immunized with antigens derived from mammals, insects, yeast or bacteria. 
     
     
         20 . The method of  claim 18 , further comprising purifying the plurality of IgY antibodies from the neutralized supernatant by gel filtration, anion exchange, and/or affinity chromatography.