Abstract

Background: Lithium heparin plasma from gel separator tubes has one major advantage over serum it can be centrifuged without delay. The major disadvantage is it contains a large number of cells, cell stroma and fibrin which renders it unsuitable for delayed testing of some analytes e.g. potassium.

Methods: BD tubes, plasma separator tube - PST, Barricor tube, rapid serum tube - RST and serum separator tube-SST were evaluated for stability of potassium, glucose, LDH and phosphate at different storage time points and centrifugation settings from 22 participants. Additionally tubes from a participant were centrifuged at 3000g, and the buffy coat containing sample was then transferred into a Cytospin centrifuge to prepare slides for staining and content examination.

Results: The Barricor tube showed decreased changes in analyte concentrations compared with the PST tube. The stability of analytes was best in the RST and at 3000g across all tubes. The buffy coat study showed the PST tube had the largest number cells present.

Conclusion: The Barricor tube offers improvement in lithium heparin plasma quality due to reduced cell numbers leading to decreasing the change in potassium, LDH and phosphate results from cellular lysis and glucose results from cellular consumption upon sample storage. Based on the data from this study the Barricor tube should become the new standard for lithium heparin plasma.

Keywords: Barricor; Tubes; Plasma; Serum; Gel separator