Direct Bilirubin

Question 1

Intended use

Answer 1

Diagnostic reagent for quantitative in vitro determination of direct bilirubin in human serum or heparin plasma on automated photometric systems

Question 2

Method

Answer 2

Photometric test using 2,4-dichloroaniline (DCA)

Direct bilirubin in presence of diazotized 2,4-dichloroaniline forms a red colored azocompound in acidic solution.

Question 3

Components and Concentrations of Reagent 1

Answer 3

EDTA-Na2 - 0.1 mmol/L
NaCl - 150 mmol/L
Sulfamic acid - 100 mmol/L

Question 4

Components and Concentrations of Reagent 2

Answer 4

2,4-Dichloroaniline - 0.5 mmol/L
HCl - 900 mmol/L
EDTA-Na2 - 0.13 mmol/L

Question 5

Warnings and Precautions of Reagent 1 & 2:

Answer 5

H290 - may be corrosive to metals
P234 - keep only in original packaging
P390 - absorb spillage to prevent material damage

Question 6

Other warnings and precautions:

Answer 6

• In very rare cases, samples of patients with gammopathy might give falsified results
• Eltrombopag medication leads to falsely low or high results in patient samples.
• Please refer to the safety data sheets and take the necessary precautions for the use of laboratory reagents. For diagnostic purposes, the results should always be assessed with the patient’s medical history, clinical examinations and other findings

Question 7

Specimen

Answer 7

Human serum or heparin plasma

Question 8

Stability of specimen:

Answer 8

2 days at 20 – 25°C
7 days at 4 – 8°C
6 months at –20°C
in case of immediate freezing.

Question 9

Assay Procedure:

Wavelength

Answer 9

545/658 nm

Question 10

Assay Procedure:

Temperature

Answer 10

37°C

Question 11

Assay Procedure:

Measurement

Answer 11

Endpoint

Question 12

Assay Procedure:

Sample/Calibrator

Answer 12

3.5 µL

Question 13

Assay Procedure:

Reagent 1

Answer 13

80 µL

Question 14

Assay Procedure:

Reagent 2

Answer 14

20 µL

Question 15

Assay Procedure:

Addition reagent 2

Answer 15

Cycle 19 (286 s)

Question 16

Assay Procedure:

Absorbance 1

Answer 16

Cycle 17/18 (230/244 s)

Question 17

Assay Procedure:

Absorbance 2

Answer 17

Cycle 41/42 (586/600 s)

Question 18

Assay Procedure:

Calibration

Answer 18

Linear

Question 19

Calibrators and Controls:

Recommended for calibration

Answer 19

DiaSys TruCal U

Question 20

Calibrators and Controls:

Calibrator values has been made traceable to the manual ________.

Answer 20

Jendrassik-Gróf test

Question 21

Calibrators and Control:

Use ________ for internal quality control

Answer 21

DiaSys Trulab N and P

Question 22

When values exceed the measuring range of up to 10 mg/dL, samples should be

Answer 22

Diluted

Calculation: 1 + 1 with NaCl solution (9 g/L) and the result multiplied by 2

Question 23

Limit of Detection:

Answer 23

0.01 mg/dL

Question 24

Interfering substances:

Answer 24

Ascorbic acid - 30 mg/dL
Hemoglobin (interferes at low concentration)
Lipemia (TAG) - 600 mg/dL

Question 25

Reference range:

Answer 25

Adults - ≤ 0.2 mg/dL
Children - ≤ 3.4 µmol/L