An Update on Underfilled Tubes

With thanks to Margaret Fritsma MA SBB for the heads-up, here is a comprehensive open-access article detailing the effect of short draw tubes on many assays: de Koning L, Ezra S, Cai F, et al. Underfilled tubes revisited: What blood tests can be reported on short draws? Am J Clin Pathol. 2025:aqaf109. doi: 10.1093/ajcp/aqaf109. PMID: […]

Comments (0)

Specimen Management

Oct 15 2025

george

Underfilled Citrate Tubes

Hi George. My name is Reynaldo Caparros. I know that it has been taught and drilled in our knowledge on how we should properly fill up blue tops. This has also resulted in numerous delays in patient care. My question is, are there any studies that have been done to check the possibility that short […]

Specimen Management

Does Chewing Gum Affect Fasting Blood Specimens?

On September 23, 2025, friend and colleague Dave McGlasson had a fasting blood specimen drawn. The collector noted that he was chewing gum and explained that the gum, although sugar-free, could affect the results. McGlasson messaged, “Chewing sugar-free gum should be avoided before a fasting blood draw because it can elevate certain blood levels, including […]

Specimen Management

Reprise: In Vitro DOAC Removal

At the request of the Annals of Blood editor, here is a link to our 2020 article on in vitro DOAC removal agents, which has attracted >5000 page views: McGlasson DL Fritsma GA. In vitro detection and removal of direct oral anticoagulants from patient plasma specimens. Ann Blood 2020;5:25 | http://dx.doi.org/10.21037/aob-20-16. The article was first […]

Comments (0)

Anticoagulant Therapy

Aug 16 2025

george

July 2025 CAP Today: A Deep Dive Into Key Hemostasis Testing Variables

Click A Deep Dive Into Key Hemostasis Testing Variables for an in-depth review of preanalytical hemostasis specimen concerns. The CAP article features Andrew Goodwin MD, professor, Department of Pathology and Laboratory Medicine, University of Vermont Larner College of Medicine, and medical director of the thrombosis and hemostasis section, University of Vermont Medical Center; and Dr. […]

Specimen Management

Impact of Sodium Citrate Levels on Coagulation Assays

Click here to see a poster describing the effects of varying citrate concentrations on clot-based assays: Rahman M, Bruhm M, Black KM, Sadeghi-Khomami A. Impact of sodium citrate levels in coagulation assays: A controlled ex-vivo study. Poster Presented at ISLH 2025. The findings will help us determine the effects of underfilling or overfilling blue-closure tubes […]

Specimen Management

Does Antiseptic Alcohol Cause Hemolysis?

Collectors routinely disinfect phlebotomy sites with isopropyl alcohol (IPA). We like to repeat a commonly held myth from the “data-free zone” that failure to allow the alcohol to dry before venipuncture causes patient discomfort, blood specimen hemolysis, and blood specimen dilution. The myth is addressed in the attached open access article, Sarmah D, Sharma B, […]

Specimen Management

Underfilled or Overfilled Coagulation Specimen Tubes

The CLSI H21 standard lists causes for coagulation specimen rejection, including hemolysis, icterus, lipemia, clotted specimens, underfilled tubes, and overfilled tubes. In most applications, underfilling is defined as a specimen comprising less than 90% of the stated volume. Most blue-closure tubes contain 0.3 mL of 3.2% sodium citrate and are calibrated to collect 2.7 mL […]

Specimen Management

How to Improve Lab Testing

From Heather DeVries: In the scope of the whole world, how do labs search for new ways to improve their laboratory testing? Would it just be typing in the search bar, or are there ways to find the latest information randomly while looking for other things? George replies, Heather, my surface-level response is to suggest […]

Specimen Management

More on CAP Specimen Requirements

In follow-up to my February 25, 2025 post, New CAP Survey Coag POC Requirements, I asked Dr. Andrew Goodwin, “Does CAP address courier specimen management? I see specimens collected at regional clinics that stand in a door-mounted specimen box for extended periods. I also wonder whether couriers have equipment maintaining coag specimen temperatures between 18 […]

Comments (2)

Blog

Specimen Management

An Update on Underfilled Tubes

Underfilled Citrate Tubes

Does Chewing Gum Affect Fasting Blood Specimens?

Reprise: In Vitro DOAC Removal

July 2025 CAP Today: A Deep Dive Into Key Hemostasis Testing Variables

Impact of Sodium Citrate Levels on Coagulation Assays

Does Antiseptic Alcohol Cause Hemolysis?

Underfilled or Overfilled Coagulation Specimen Tubes

How to Improve Lab Testing

More on CAP Specimen Requirements

George Fritsma MS MLS

Cheat Sheets from George

Questions or Comments?

Quick Question