Stability of total plasma homocysteine in perinatology

Background: Typical assay methods for total homocysteine in human plasma involve EDTA-containing whole blood. Unfortunately, rapid increases of the plasma homocysteine concentrations due to cellular export are observed when the EDTA-containing samples are not stored on ice and processed shortly after collection. This is a cumbersome procedure in perinatal settings, whereby delivery usually takes place at unpredictable times. Methods: The stability of homocysteine was assessed from six placental and neonatal blood samples collected in citrate buffer. Samples were stored at 4 degreesC and tested at regular intervals for the first 24 h. Results: There was no statistical difference in homocysteine concentrations as observed over the study storage period (mean coefficient of variation [CV] 4.9%). Conclusions: Citrated samples can be left in a refrigerator for at least 24 h with no effect on the plasma homocysteine concentrations. (C) 2002 Elsevier Science B.V All rights reserved.