The Effect of Clot-Activator and Storage Time on Estimation of Free  triiodothyronine T3 levels in Blood Samples

Farhana Mukhtar; Madeeha Cheema; Amina Khalid; Amtul Jamil Sami; Sumbul Mehmood

doi:10.51273/esc19.715114

Authors

Farhana Mukhtar
Madeeha Cheema
Amina Khalid
Amtul Jamil Sami
Sumbul Mehmood

DOI:

https://doi.org/10.51273/esc19.715114

Keywords:

Triodothyronine (FT3), thyroxine (T4), blood collecting tubes (BCT), clot activator

Abstract

Objective: To find out the effect of clot-activator and storage time on estimation of free
triodothyronine (FT3) in blood samples. .
Methods: Thirty five normal volunteers from general population were selected. Their blood
samples were collected into two different types of Greigor Bio-One blood collecting tubes (BCT).
Blood collecting tubes of first type were without clot activator and second type of BCT was with clot
activator. Blood samples of first type of BCT were used to analyse the effect of storage time on
free triodothyronine (FT3) estimation. These tubes were centrifuged and separated serum was
preserved into 4 BCT without clot activator and labelled as first day, 24 hours, 48 hours and 96
hours. The serum of these tubes was estimated for FT3 at the intervals as labelled on the BCT.
Free triiodothyronine estimation was done using Beckman coulter kit. To analyse the effect of clot
activator on FT3 estimation, blood samples collected in BCT with clot activator were allowed to
clot, serum was separated and FT3 estimation was done on the same day.
Results: Results of this study showed no statistical significance of results after 24h (p=0.256) by
one way ANOVA analysis and Post Hoc test, but significant difference in values of FT3
concentration was observed after delayed analysis of 48 and 96 hours with P value(p=0.03).
Paired Samples Test-BCT with and without clot activator had variation in results and significance
(p =0.002) were analysed by statistical analysis.
Conclusions: This study concludes that, FT3 concentration variation was not statistically
significant when it was estimated within 24 hours, but a false increase was observed after a delay
of 48 to 96 hours. Samples of BCT without clot activator showed precise results of FT3 estimation
when compared to the results of samples of BCT with clot activator. Therefore, BCT without clot
activator should be preferred for collection of blood sample for FT3 estimation.