The effects of freeze-thaw on β-trace protein and β2-microglobulin assays after long-term sample storage

Clin Biochem. 2012 Jun;45(9):694-6. doi: 10.1016/j.clinbiochem.2012.02.027. Epub 2012 Mar 9.


Objectives: To evaluate the effect of a freeze-thaw cycle on β-trace protein (βTP) and β2-microglobulin (β2M).

Design and methods: We compared βTP and β2M concentrations before and after a single freeze-thaw cycle in long-term stored samples from 172 participants of the Third National Health and Nutrition Examination Survey (NHANES III).

Results: Measurements of βTP and β2M before and after freeze-thaw were highly correlated with Spearman's coefficients of 0.90 and 0.99, respectively. Serum concentrations of βTP were slightly lower after freeze-thaw (-0.05 mg/L, P=0.006). Measurements of β2M did not differ before and after freeze-thaw (P=0.35).

Conclusions: βTP and β2M measurements were robust to a single freeze-thaw cycle, although β2M appeared more stable than βTP. These results have implications for future studies of these biomarkers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • Blood Specimen Collection
  • Cryopreservation*
  • Freezing
  • Humans
  • Intramolecular Oxidoreductases / blood*
  • Lipocalins / blood*
  • Middle Aged
  • Reproducibility of Results
  • Time Factors
  • beta 2-Microglobulin / blood*


  • Biomarkers
  • Lipocalins
  • beta 2-Microglobulin
  • Intramolecular Oxidoreductases
  • prostaglandin R2 D-isomerase