Hemostasis Today

May, 2026
May 2026
M T W T F S S
 123
45678910
11121314151617
18192021222324
25262728293031
Sivasooriar Sivaneson: Every Drop of Blood Matters in Pre-Analytical Laboratory Quality
May 26, 2026, 09:30

Sivasooriar Sivaneson: Every Drop of Blood Matters in Pre-Analytical Laboratory Quality

Sivasooriar Sivaneson, Senior Advisor and Consultant of Pathology, Senior Manager of the Core Laboratory at Gribbles Pathology, shared a post on LinkedIn:

Every Drop Matters: The Hidden Impact of Underfilled Blood Collection Tubes

One of the most common yet underestimated pre-analytical errors is underfilled blood collection tubes. What may seem like a small issue can significantly affect result reliability due to an incorrect blood-to-additive ratio.

Here’s how underfilling can impact different sample types:

EDTA Tube (CBC – Purple Top):

Excess EDTA may alter blood cell morphology and counts, leading to:

  • Falsely low MCV due to red cell shrinkage
  • Falsely low hematocrit (HCT) values
  • Platelet clumping
  • Blood film artifacts affecting morphology interpretation

ESR Tube (Erythrocyte Sedimentation Rate):

An incorrect blood-to-anticoagulant ratio may produce:

  • Falsely low ESR values

Plain / Serum Tube (Red/Yellow Top):

While generally more tolerant, underfilling may still result in:

  • Inadequate serum volume for testing
  • Poor clot formation or serum separation

Fluoride Tube (Grey Top – Glucose Testing):

Incorrect blood-to-additive ratios may impair glucose preservation and reduce the tube’s ability to adequately inhibit glycolysis, potentially causing:

  • Low glucose results

Coagulation Tube (Blue Top – Sodium Citrate):

Most Critical

This tube depends on a strict 9:1 blood-to-anticoagulant ratio. Underfilling can cause:

  • Falsely prolonged PT/INR and APTT
  • Inaccurate D-dimer and coagulation factor results
  • Misinterpretation of bleeding or anticoagulation status

The reality is simple: A high-quality analyzer cannot compensate for a poor-quality specimen.

Laboratory excellence is not only about analytical performance — it begins with proper specimen collection, correct fill volume, and strong pre-analytical quality practices.

A simple reminder to every healthcare professional involved in specimen collection:

Fill the tube to the mark — because every drop matters, and every result matters.”

Stay updated with Hemostasis Today.