323 lab 8

What is the intended use of the Liquid Glucose (Oxidase) Reagent Set?

For the quantitative determination of glucose in serum, for in vitro diagnostic use only.

What clinical significance does glucose determination in serum have?

It is commonly performed for the diagnosis and treatment of diabetes mellitus.

What is the principle behind glucose oxidation in this assay?

Glucose is oxidized by glucose oxidase to gluconate and hydrogen peroxide, which then produces a quinoneimine dye measured at 500 nm.

What are the primary components of the reagent composition?

Glycose Oxidase (12,000 u/l), Peroxidase (> 1,000 u/l), 4-AAP (>0.3mM), Phenol (4mM), Buffer, non-reactive stabilizers.

What should be done if the reagent shows turbidity or microbial growth?

The reagent should not be used.

What type of serum samples are recommended for glucose determination?

Non-hemolyzed serum or heparinized plasma.

How long can glucose in serum remain stable when stored refrigerated?

Twenty-four hours.

Which sample interference can produce falsely elevated glucose values?

Grossly lipemic samples.

What is the absorbance range for the wavelength used in this assay?

500 nm.

What is the procedure to be followed if glucose concentration exceeds the linear range of the assay?

Samples that exceed 500 mg/dl should be diluted with an equal volume of saline and re-assayed.

What is the formula for calculating glucose concentration based on absorbance?

Abs. (Patient) x Concentration of Standard / Abs. (Standard).

How can results in mg/dl be converted to SI units (mmol/L)?

Multiply mg/dl by 10 and then divide by 180.

What are the expected normal glucose values for human serum?

70-105 mg/dl.

What is the sensitivity of the Liquid Glucose (Oxidase) reagent?

1 mg/dl of glucose gives an absorbance of 0.002.

Which method was modified by Trinder to quantify hydrogen peroxide?

The peroxidase-phenol-aminophenazone system.

How should the reagent be stored?

Refrigerated at 2-8°C.

What is the calibration standard recommended for this assay?

A NIST-traceable glucose standard (100mg/dl) or serum calibrator.

Which document outlines the procedures for blood specimen collection?

NCCLS document H4-A3.