: Biological samples are often frozen and stored for years and/or thawed multiple times, thus assessing their stability on long-term storage and repeated freeze-thaw cycles is crucial. The study aims were to assess:-the long-term stability of two major enzymatic and non-enzymatic metabolites of arachidonic acid, i.e. urinary 11-dehydro-thromboxane-(Tx) B2, 8-iso-prostaglandin (PG)F2α, and creatinine in frozen urine samples;-the effect of multiple freeze-thaw cycles. Seven-hundred and three urine samples measured in previously-published studies, stored at -40 °C, and measured for a second time for 11-dehydro-TxB2 (n = 677) and/or 8-iso-PGF2α (n = 114) and/or creatinine (n = 610) were stable over 10 years and the 2 measurements were highly correlated (all rho = 0.99, P < 0.0001). Urine samples underwent 10 sequential freeze-thaw cycles, with and without the antioxidant 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (10 mM); urinary 11-dehydro-TxB2 and creatinine were stable across all cycles (11-dehydro-TxB2: 100.4 ± 21%; creatinine: 101 ± 7% of baseline at cycle ten; n = 17), while 8-iso-PGF2α significantly increased by cycle 6 (151 ± 22% of baseline at cycle ten, n = 17, P < 0.05) together with hydrogen peroxide only in the absence of antioxidant. Arachidonic acid metabolites and creatinine appear stable in human urines stored at -40 °C over 10 years. Multiple freeze-thaw cycles increase urinary 8-iso-PGF2α in urine samples without antioxidants. These data are relevant for studies using urine samples stored over long-term and/or undergoing multiple freezing-thawing.

Petrucci, G., Hatem, D., Langley, R., Cleary, S., Gentry-Maharaj, A., Pitocco, D., Rizzi, A., Ranalli, P., Zaccardi, F., Habib, A., Rocca, B., Effect of very long-term storage and multiple freeze and thaw cycles on 11-dehydro-thromboxane-B2 and 8-iso-prostaglandin F2α, levels in human urine samples by validated enzyme immunoassays, <<SCIENTIFIC REPORTS>>, 2024; 14 (1): 5546-5556. [doi:10.1038/s41598-024-55720-3] [https://hdl.handle.net/10807/269594]

Effect of very long-term storage and multiple freeze and thaw cycles on 11-dehydro-thromboxane-B2 and 8-iso-prostaglandin F2α, levels in human urine samples by validated enzyme immunoassays

Petrucci, Giovanna
Primo
Methodology
;
Hatem, Duaa
Data Curation
;
Pitocco, Dario
Conceptualization
;
Rizzi, Alessandro
Methodology
;
Rocca, Bianca
Ultimo
Writing – Review & Editing
2024

Abstract

: Biological samples are often frozen and stored for years and/or thawed multiple times, thus assessing their stability on long-term storage and repeated freeze-thaw cycles is crucial. The study aims were to assess:-the long-term stability of two major enzymatic and non-enzymatic metabolites of arachidonic acid, i.e. urinary 11-dehydro-thromboxane-(Tx) B2, 8-iso-prostaglandin (PG)F2α, and creatinine in frozen urine samples;-the effect of multiple freeze-thaw cycles. Seven-hundred and three urine samples measured in previously-published studies, stored at -40 °C, and measured for a second time for 11-dehydro-TxB2 (n = 677) and/or 8-iso-PGF2α (n = 114) and/or creatinine (n = 610) were stable over 10 years and the 2 measurements were highly correlated (all rho = 0.99, P < 0.0001). Urine samples underwent 10 sequential freeze-thaw cycles, with and without the antioxidant 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (10 mM); urinary 11-dehydro-TxB2 and creatinine were stable across all cycles (11-dehydro-TxB2: 100.4 ± 21%; creatinine: 101 ± 7% of baseline at cycle ten; n = 17), while 8-iso-PGF2α significantly increased by cycle 6 (151 ± 22% of baseline at cycle ten, n = 17, P < 0.05) together with hydrogen peroxide only in the absence of antioxidant. Arachidonic acid metabolites and creatinine appear stable in human urines stored at -40 °C over 10 years. Multiple freeze-thaw cycles increase urinary 8-iso-PGF2α in urine samples without antioxidants. These data are relevant for studies using urine samples stored over long-term and/or undergoing multiple freezing-thawing.
2024
Inglese
Petrucci, G., Hatem, D., Langley, R., Cleary, S., Gentry-Maharaj, A., Pitocco, D., Rizzi, A., Ranalli, P., Zaccardi, F., Habib, A., Rocca, B., Effect of very long-term storage and multiple freeze and thaw cycles on 11-dehydro-thromboxane-B2 and 8-iso-prostaglandin F2α, levels in human urine samples by validated enzyme immunoassays, <<SCIENTIFIC REPORTS>>, 2024; 14 (1): 5546-5556. [doi:10.1038/s41598-024-55720-3] [https://hdl.handle.net/10807/269594]
File in questo prodotto:
File Dimensione Formato  
Sci Reports.pdf

accesso aperto

Licenza: Creative commons
Dimensione 2.97 MB
Formato Adobe PDF
2.97 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10807/269594
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
social impact