ENRICHMENT AND CONCENTRATION OF SELECT PRODUCT ISOFORMS BY OVERLOADED BIND AND ELUTE CHROMATOGRAPHY

1 . A method for enhancing or increasing the concentration of biological product in a final mixture, wherein said biological product has one or more selected characteristics, wherein said method comprises:

(a) allowing an initial mixture of biological products with and without said selected characteristics to contact a chromatography medium wherein the quantity of biological products in said initial mixture exceeds the binding capacity or the dynamic binding capacity of said chromatography medium;

(b) allowing biological product not having said one or more selected characteristics to be separated by said chromatography medium; and

(c) recovering a final mixture of biological products from said chromatography medium wherein said final mixture comprises an enhanced or increased concentration of biological product with one or more selected characteristics, compared to the concentration of biological product in said initial mixture.

2 . The method of claim 1 , wherein said chromatography medium is selected from the group consisting of:

a) ion exchange medium;

b) anion exchange medium;

c) cation exchange medium;

d) hydroxyapatite medium;

e) hydrophobic interaction chromatography medium;

f) antibody-affinity medium;

g) immunoglobulin Fc-region affinity medium;

h) ligand-affinity medium;

i) receptor-affinity medium;

j) mixed-mode medium;

k) use of any two or more of a) through j) performed sequentially in any order.

3 . The method of claim 1 , wherein the binding capacity or dynamic binding capacity of said chromatography medium is exceeded by an amount selected from the group consisting of:

a) 10% or more;

b) 20% or more;

c) 30% or more;

d) 40% or more;

e) 50% or more;

f) 100% or more;

g) 200% or more;

h) 500% or more; and

i) 1000% or more.

4 . The method of claim 1 , wherein the binding capacity or dynamic binding capacity of said chromatography medium is exceeded by an amount selected from the group consisting of:

a) 1.5-fold or more;

b) 2-fold or more;

c) 3-fold or more:

d) 4-fold or more;

e) 5-fold or more;

f) 6-fold or more;

g) 7-fold or more;

h) 8-fold or more;

i) 9-fold or more;

j) 10-fold or more;

k) 20-fold or more;

l) 30-fold or more;

m) 40-fold or more;

n) 50-fold or more;

o) 100-fold or more; and

p) 500-fold or more.

5 . The method of claim 1 , wherein the amount of biological products recovered in the final mixture, compared to the amount of biological products in the initial mixture, is an amount selected from the group consisting of:

a) about 10% to about 80% recovered;

b) about 20% to about 60% recovered;

c) about 30% to about 60% recovered;

d) about 30% to about 50% recovered;

e) about 35% to about 50% recovered;

f) about 35% to about 45% recovered;

g) about 40% to about 45% recovered;

h) about 40% to about 50% recovered;

i) about 45% to about 50% recovered;

j) about 10% recovered;

k) about 15% recovered;

l) about 20% recovered;

m) about 25% recovered;

n) about 30% recovered;

o) about 35% recovered;

p) about 40% recovered;

q) about 45% recovered;

r) about 50% recovered;

s) about 55% recovered;

t) about 60% recovered;

u) about 65% recovered;

v) about 70% recovered;

w) about 75% recovered; and

x) about 80% recovered.

6 . The method of claim 1 , wherein the concentration of biological product with one or more selected characteristics is increased or enhanced, compared to the initial mixture of biological products, by an amount selected from the group consisting of:

a) at least about 5%;

b) at least about 10%;

c) at least about 20%;

d) at least about 30%;

e) at least about 40%;

f) at least about 50%;

g) at least about 60%;

h) at least about 70%;

i) at least about 80%; and

j) at least about 90%.

7 . The method of claim 1 , wherein the selected characteristic (or characteristics) is (are) selected from the group consisting of:

a) degree of net negative charge at a set pH value;

b) degree of net positive charge at a set pH value;

c) degree of hydrophobicity;

d) degree of hydrophilicity;

e) quantity and/or type of carbohydrate content;

f) quantity and/or type of N-linked glycosylation content;

g) quantity and/or type of O-linked glycosylation content;

h) total sialic acid content; and

i) any one or more of a) through h).

8 . The method of claim 1 , wherein the biological product is selected from the group consisting of:

a) a protein;

b) an antibody or fragment thereof;

c) a polypeptide comprising an extracellular receptor ligand-binding domain;

d) a receptor ligand;

e) a heterologous fusion protein;

f) a fusion protein comprising an immunoglobulin Fc-region; and

g) a fusion protein comprising an extracellular receptor ligand-binding domain and an immunoglobulin Fc-region.

9 . The method of claim 1 , wherein said method further comprises recovery of said biological product at a manufacturing scale.

10 . The method of claim 8 , wherein said method further comprises recovery of a therapeutically useful biological product.

11 . The method of claim 2 , wherein said method further comprises recovery of said biological product at a manufacturing scale.

12 . The method of claim 3 , wherein said method further comprises recovery of said biological product at a manufacturing scale.

13 . The method of claim 4 , wherein said method further comprises recovery of said biological product at a manufacturing scale.

14 . The method of claim 5 , wherein said method further comprises recovery of said biological product at a manufacturing scale.

15 . The method of claim 6 , wherein said method further comprises recovery of said biological product at a manufacturing scale.

16 . The method of claim 7 , wherein said method further comprises recovery of said biological product at a manufacturing scale.

17 . The method of claim 8 , wherein said method further comprises recovery of said biological product at a manufacturing scale.