Removal of heparin from blood plasma samples using an insoluble protamine reaction product

DETAILED DESCRIPTION We claim: 1.
A method for removing substantially all heparin from a heparin-containing blood plasma test sample which comprises: A.
Adding from about 10 to about 20 mg.
of the insoluble protamine/glutaraldehyde reaction product prepared by incubating an aqueous solution containing: I.
From about 1.
5 to about 2.
5 grams of protamine sulfate; II.
From about 20 to about 30 milliliters of water; III.
From about 20 to about 30 milliliters of phosphate buffer; and IV.
From about 6 to about 9 milliliters of a 10% solution of glutaraldehyde in phosphate buffer; at a pH of from about 6 to about 12 and a temperature of from about 4.
degree.
C.
to about 10.
degree.
C.
overnight; per milliliter of plasma to the plasma sample; B.
Agitating (A) until substantially all the heparin present in the plasma sample is adsorbed by and complexed with the insoluble protamine/glutaraldehyde reaction product; C.
Allowing (B) to stand for a time sufficient to allow precipitation of the free and complexed insoluble protamine/glutaraldehyde reaction product; D.
Removing the precipitate of (C) from the plasma sample to obtain substantially heparin-free plasma suitable for coagulation testing.
2.
A method according to claim 1 wherein, in Step A, about 14 mg.
of insoluble protamine/glutaraldehyde reaction product are added.
3.
A method according to claim 2 wherein, in Step B, the agitation is conducted for from about 10 to about 20 minutes.
4.
A method according to claim 3 wherein, in Step C, the plasma is allowed to stand for from about 2 to about 8 minutes.
5.
A method for removing substantially all heparin from a heparin-containing blood plasma test sample which comprises: A.
Adding from about 4 to about 14 mg.
of the insoluble protamine/serum albumin/glutaraldehyde reaction product, prepared by incubating an aqueous solution containing: I.
From about 0.
07 to about 0.
13 grams of serum albumin; II.
From about 0.
7 to about 1.
3 grams of protamine sulfate; III.
From about 20 to about 30 milliliters of water; and IV