Chloride Assay Kit (CL)
For quantitative determination of chloride in human serum.
The determination of chloride in serum is the most commonly performed for the diagnosis of proper hydration, osmotic pressure, and acid/base equilibrium. Elevated serum chloride values may be seen in dehydration, hyperventilation, congestive heart valve, and prostatic or other types of urinary obstruction. Low serum chloride values are found with extensive burns, excessive vomiting, intestinal obstruction, nephritis, and metabolicacidosis.
Mammalian α-amylase, which normally involves binding with calcium ion, is deactivated by removing calcium ion by adding a high concentration of EDTA in the absence of chloride anion. The deactivated α-amylase is reactivated by addition of chloride anion,which allows the calcium ion to reassociate with the enzyme. The reactivation of α-amylase activity is proportional to the concentration of chloride anion present. Ethylidene blocked pnitrophenyl-maltoheptaoside (EPS-G7) is used as the substrate. Reactivated α-amylase hydrolyzes EPS-G7 to Et-Gx and Gy-pNP. Gy-pNP is further hydrolyzed by a coupled enzyme, α-glucosidase to glucose and pNP which is quantitated colorimetrically at 405 nm. The amount of pNP formed is directly proportionalto the α-amylase.
EDTA-Ca+ + α-amylase + Cl → EDTA + α-amylase-ca2+
Et-G7-pNP + α-amylase-ca2+ → Et-Gx + Gy-pNP
Gy-pNP + α-glucosidase → glucose + pNP-glucoside
PNP-glucoside + α-glucosidase → glucose + pNP
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- White, W.L., et al., Chemistry for technologist, 3rd Ed, The C.V. Mosby Co, St. Louis, p182 (1970)
- Ono, T., et al., Clin. Chem. 34: 552-553 (1988)
- Klaus Lorentz. Clin. Chem. 46(5) 644-649 (2000)
- “National Clinical Laboratory Operating Procedures” (fourth edition), the Ministry of Health of the People’s Republic of China