No Additive / No Clot Activator Blood Collection Tubes & Serum Chemistry Testing

No Additive / No Clot Activator Blood Collection Tubes (Commonly known as: Plain Tubes, Red-Top Tubes - typically uncoated) are fundamental vacuum blood collection tubes designed for venous blood sampling. Their defining characteristic is that the tube interior contains no anticoagulants (e.g., heparin, EDTA, citrate) or clot activators (e.g., silica particles, thrombin).

• Primary Function: Blood collected into these tubes undergoes natural coagulation entirely. The clotting cascade is activated, forming a fibrin clot that traps blood cells, ultimately yielding serum upon centrifugation. This clotting process typically requires 30-60 minutes before centrifugation to separate the serum.

• Key Applications:

  • Serum Chemistry Testing: This is the primary application. The separated serum is suitable for a wide range of routine clinical chemistry tests, including electrolytes (potassium, sodium, chloride, calcium), liver function (ALT, AST, ALP, bilirubin), renal function (creatinine, BUN), glucose, lipids (cholesterol, triglycerides), total protein, and enzyme assays.

  • Serology Testing: Such as antibody tests for certain infectious diseases (requiring serum).

  • Blood Bank Testing: Some blood typing and antibody screening tests require serum samples.

  • Therapeutic Drug Monitoring (TDM): Measurement of concentrations for certain therapeutic drugs often specifies serum.

  • Specialized Research or Reference Methods: Used in research or as a reference method when complete avoidance of potential interference from anticoagulants or clot activators is critical.

• Key Characteristics: Produces samples closest to the natural clotted state of blood in vivo, eliminating potential interferences introduced by additives (e.g., anticoagulant binding ions, clot activator affecting enzyme activity or releasing substances). The main drawback is the longer processing time required for clot formation and serum separation, making it unsuitable for stat testing.

Intended Use/Setting: Clinical laboratories (chemistry, immunology, blood bank) and research institutions performing tests requiring serum samples.