B - Chapter VI: Carbohydrates

use (?)

whole blood values (?) lower than serum or plasma

erum or plasma should be refrigerated and separated from the cells (?) to prevent substantial loss thru glycolysis

separated unhemolyzed serum at rm temperature is stable for

preferred additive :

: approximately 8 - 10 hr fast (not >16 hr)

: immediate processing to prevent bacterial utilization of glucose

: only for monitoring of diabetics and not for diagnosis

Chemical methods − done in an

− glucose + boiling water —-> (?) (enol anion form) : reduce metallic ions

Alkaline Copper reduction Tests

total reducing substances (true reducing substances and saccharoids) measured

barium sulfate enables measurement of true reducing substances only

Campbell and King method

neocuproine (7,9- dimethyl-1,10-phenanthroline) —> cuprous-neocuproine complex (yellow-orange)

arsenomolybdic acid —> arsenomolybdenum blue

phosphomolybdic acid —> phosphomolybdenum blue

Alkaline Ferric reduction tests

− reverse colorimetric method − more specific than copper reduction

− ferricyanide —> ferrocyanide

Condensation methods

Ortho-toluidine method by Dubowski (reference method)

based on the ability of carbohydrates to form Schiff bases with aromatic amines

glucose + ortho-toluidine —-> N-glycosylamine: Schiff base (green) 630 nm