Print

VETSPEC™REAGENTS - Bromide

Intended Use

For IN VITRO diagnostic use in the quantitative determination of Bromide in serum using manual or automated applications.

Method Principle

Under acid conditions, Chloride ions from Gold Trichloride displace Bromide ions present in the serum sample. The dissociated Bromide ions then engage in a subsequent reaction with Gold to produce a colored complex (AuBr3) with maximum absorption at 380 nm. The intensity of the color thus produced is directly proportional to the concentration of Bromide ions in the serum sample. The reaction scheme below illustrates the steps that occur in this Bromide method.

AuCl3 + 3Br- ────────> AuBr3 + 3Cl-

*The formation of Gold Chloride may also be accompanied by the formation of AuBrCl2 or AuBr2Cl.

Reagent Storage And Stability

Store the Bromide Sample Diluent reagent at room temperature. Store the Bromide Color Reagent at 2-8°C. When stored as directed, these reagents are stable until expiration date stated on the label.

Working Reagent Preparation

The Bromide reagents are packaged ready for use. No preparation is required. Once opened, the Working Sample Diluent Reagent (R1) is stable until the expiration date indicated on the label. The Bromide Color Reagent (R2) once opened is stable for 60 days at 2-8°C.

Method Performance Characteristics

Sensitivity: Using a path length of 1 cm, a Δ-absorbance of 0.0016-0.0024 per mg/mL should be obtained.
Linearity: In this procedure there is no significant nonlinearity over the range of 0-3 mg/mL.
Precision: Precision data was obtained using three levels of protein-based controls and following the NCCLS EP5-T2 procedure (3). The following results were observed.

Bromide

Within-Run Precision

Total Precision

MEAN

SD

CV

SD

CV

mg/mL

mg/mL

%

mg/mL

%

0.50

0.034

6.80

0.029

7.80

1.00

0.034

3.40

0.409

4.90

1.50

0.036

2.40

1.070

7.10

 

Accuracy

Correlation studies were carried out between this automated Bromide method (Y) and the manual, Gold Chloride, free protein filtrate method (2) as reference (X). Canine serum samples were assayed and the results compared by the least squares regression. The following statistics were observed:

Correlation Data

Parameter

Data Observed

N

25

Range

0.6 – 4.1

Mean of Y

1.690

Mean of X

1.760

Regression

Y = 1.010x - 0.110

Correlation

r = 0.940

Sy,x

0.310