🔬 1. Direct Bilirubin (Conjugated) — Diazo Method

Principle

Direct (conjugated) bilirubin reacts directly with diazotized sulfanilic acid to form azobilirubin, a reddish-purple complex.

• Absorbance: ~540–560 nm

• Method: Endpoint or timed endpoint

• No accelerator needed (only conjugated bilirubin reacts)

Reagent Components

• Sulfanilic acid

• Sodium nitrite

• Hydrochloric acid (for diazo formation)

• Buffer (acetate)

• Preservatives

Some manufacturers supply:

• R1: Buffer

• R2: Diazo reagent

🧪 2. Total Bilirubin — Diazo Method (Accelerated)

Principle

Unconjugated bilirubin requires an accelerator to react with the diazo reagent.

Common accelerators:

• Caffeine–benzoate

• Surfactants

• Methanol or DMSO (older methods)

Total bilirubin reacts with diazo reagent to form azobilirubin.

• Absorbance: ~540–560 nm

• Method: Endpoint or timed endpoint

Reagent Components

• Caffeine-benzoate accelerator

• Sulfanilic acid

• Sodium nitrite

• Acid buffer

• Stabilizers and preservatives

Formats:

• 1-reagent systems (common today)

• 2-reagent systems (R1 accelerator + R2 diazo reagent)

Key Features & Specifications

• Type: Fully automatic, random-access chemistry analyzer with open reagent system (can use reagents from different suppliers).

• Throughput: Approximately 120 tests per hour.

• Reagent capacity: Typically around 80 positions (40 for R1 + 40 for R2) with ~40 sample positions.

• Reaction cuvettes: Around 50 cuvettes; reaction volume ~150 µL to ~330 µL.

• Optical system: Multi-wavelength detection (340 nm, 405 nm, 450 nm, 505/510 nm, 546 nm, 578 nm, 630 nm, 700 nm).

• Reagent tray cooling: Continuous cooling system maintaining 2 °C–14 °C.

• Sample & reagent probe features: Liquid level detection, collision protection, automatic probe cleaning and adjustment.

• Calibration & quality control: Supports linear and nonlinear calibration, multi-point calibration, Westgard QC plotting.

• Physical footprint: Approximately 750 mm × 550 mm × 490 mm; weight ~70 kg.

Key Features

• Accurate Rh (D) Detection: Formulated to deliver clear, dependable agglutination results when testing for the D antigen.

• Ready-to-Use Liquid Reagent: No further dilution required—convenient for routine use and emergency blood typing.

• 10 ml Volume: Ideal for moderate to high sample workloads while minimizing wastage.

• High Sensitivity & Specificity: Engineered to reduce false reactions and ensure consistent, trustworthy outcomes.

• Quality-Assured Manufacturing: Produced under stringent standards to maintain stability, clarity, and performance.

• Compatible With Standard Testing Methods: Suitable for slide, tube, and immediate spin techniques, depending on lab protocol.

A ready-to-use reagent for blood typing. It detects the B antigen on red blood cells, helping determine a person’s ABO blood group. Ideal for hospitals, clinics, and blood banks, it ensures accurate and reliable blood grouping results.