Assay process with non-boiling denaturation

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Reagents typically used in practice of the radioassay process of the invention may comprise:
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ZERO STANDARD Polymer base containing buffer
and sodium azide.

VITAMIN STANDARD
Reconstituted standards
contain vitamin B.
sub.
12 (cyanoco-
balamin) and folate (N--methyl-
tetrahydrofolate) as indicated
below, in a polymer base con-
taining buffer and sodium
azide.

Vitamin B.
sub.
12
Folate
pg/ml ng/ml
50 1.
5
150 3.
0
400 6.
0
1000 10.
0
2000 20.
0
REDUCING AGENT Aqueous solution of dithio-
threitol (0.
26 molar -
40 grams/liter).

EXTRACTANT Sodium hydroxide and 0.
01%
potassium cyanide in water.

TRACER Contains less than 1.
5 .
mu.
Ci of
57-Co cyanocabalamin, and less
than 3.
0 .
mu.
Ci of 125-I folate
in borate buffer containing
sodium chloride, indicator
dye, and sodium azide.
Cobal-
amin specific activity is
2 Ci/.
mu.
mole.

[A portion of the extractant
and of the tracer are mixed -
freshly before each assay
typically 100 microliters of
each) - to produce a master
tracer reagent.
]
BLANK REAGENT Borate-phosphate buffer with
protein and sodium azide.

BINDER Purified intrinsic factor
and .
beta.
-lactoglobulin in borate-
phosphate buffer with protein
and sodium azide