Green Top Heparin Blood Collection Tubes (Lithium Heparin)

What Are Green Top Heparin Tubes?

Green Top Heparin Tubes are vacuum blood collection tubes containing lithium or sodium heparin, specifically used for immediate plasma separation in electrolyte analysis, blood gas testing, and clinical chemistry.

Hawach Green Top Tubes provide rapid anticoagulation without affecting most biochemical analytes, making them suitable for hospitals, diagnostic laboratories, and automated analyzer systems.

Clinical Role in Plasma-Based Testing

Green Top Heparin Tubes are widely used in clinical laboratories for plasma chemistry and blood gas testing, especially in time-sensitive diagnostic workflows.

They are commonly used for:

• Clinical chemistry testing (liver and kidney function)
• Electrolyte analysis (Na⁺, K⁺, Ca²⁺, Cl⁻)
• Blood gas analysis (pH, pCO₂, pO₂)
• Cardiac marker testing
• Hormone and enzyme assays
• Toxicology and drug monitoring

These tests require stable plasma samples without clot formation.

How Heparin Prevents Blood Clotting

Heparin prevents coagulation in collected blood samples by enhancing antithrombin III activity, which inhibits thrombin and blocks fibrin clot formation, maintaining blood in a stable anticoagulated plasma state for analysis. This ensures plasma remains suitable for laboratory testing immediately after collection.

Mechanism of Action

1. Blood is collected into a vacuum tube coated with lithium heparin
2. Heparin activates antithrombin III
3. Thrombin and coagulation factors are inhibited
4. Fibrin formation is blocked
5. Blood remains in anticoagulated plasma state
6. Sample is ready for centrifugation and analysis

Heparin Plasma Stability & Processing Window

• Centrifugation should occur within 30–60 minutes of collection for optimal analyte stability.
• Heparinized plasma remains stable for most chemistry analytes (e.g., electrolytes, enzymes) for up to 4 hours at room temperature.
• Delayed processing (>2 hours) may cause:
– Potassium shift (pseudohyperkalemia if hemolysis occurs)
– Glucose decrease (5–10% per hour if cells remain in contact with plasma)
– Enzyme leakage (LDH, AST from cellular damage)
• Timely centrifugation and plasma separation are critical for accurate results.

Key Features of Hawach Green Top Tubes

• High-purity lithium / sodium heparin anticoagulant
• Rapid plasma separation performance
• Minimal interference with biochemical analytes
• Precise vacuum control for accurate draw volume (±5%)
• Medical-grade PET or glass materials
• Smooth inner wall reduces hemolysis risk
• Compatible with automated chemistry analyzers
• Stable batch-to-batch production consistency
• Green color coding for easy identification

Position in Blood Collection Sequence (CLSI Context)

Green Top Heparin Tubes are typically collected after serum tubes and before EDTA tubes to prevent additive interference and ensure accurate laboratory results.

Green Top vs Other Blood Collection Tubes

Main Applications

• Clinical chemistry testing
• Electrolyte panel analysis
• Blood gas and acid-base testing
• Cardiac marker detection
• Liver and kidney function tests
• Hormone and metabolic testing
• Emergency diagnostic workflows

Why Tube Quality Affects Plasma Accuracy

Pre-analytical factors directly influence laboratory results. Common risks include:

• Inconsistent heparin coating
• Hemolysis due to poor tube design
• Incorrect blood-to-additive ratio
• Delayed mixing after collection
• Vacuum instability affecting sample volume

High-quality tubes ensure stable plasma performance and reliable test results.

Hawach Manufacturing Advantages

Hawach Green Top Heparin Tubes are manufactured under strict quality systems to ensure consistent diagnostic performance:

• Precise heparin coating control
• Vacuum tolerance accuracy (±5%)
• Uniform additive distribution
• Smooth inner wall surface treatment
• 100% leak and vacuum integrity testing
• Batch traceability for laboratory compliance

Specifications

OEM & Bulk Supply Options

• Private label customization
• Custom packaging and labeling
• OEM branding support
• Flexible MOQ options
• Global export logistics
• Full batch traceability system

Frequently Asked Questions

What are Green Top Heparin Tubes used for?

They are used for plasma-based laboratory testing including clinical chemistry, electrolyte analysis, and blood gas testing.

Why is heparin used in these tubes?

Heparin prevents blood clotting by enhancing antithrombin III activity, allowing plasma to remain stable for testing.

Are Green Top Tubes suitable for all biochemical tests?

They are suitable for most chemistry and blood gas tests, but not for coagulation studies or certain specialized assays.

How should Green Top Tubes be handled?

They should be gently inverted 8–10 times immediately after collection and processed promptly for centrifugation.

How long is heparinized plasma stable?

Heparinized plasma remains stable for most chemistry analytes for up to 4 hours at room temperature; centrifugation within 30–60 minutes is recommended.

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