ADAM-12 stability in first trimester maternal serum.

BACKGROUND

Maternal serum A Disintergrin And Metaloprotease-12 (ADAM-12) has been proposed as a marker for prenatal screening of chromosomal abnormalities, pre-eclampsia and other adverse pregnancy outcomes. In this study, we examine the stability of ADAM-12 with time and at different temperatures.

METHODS

Maternal serum and whole blood pools were stored at 30 degrees C, room temperature and refrigerator temperature or subjected to repeated freeze-thaw cycles. ADAM-12 was measured at set time points using an automated DELFIA research assay.

RESULTS

Using a 10% change in concentration as a limit of stability, ADAM-12 is stable in serum for less than 15 h at 30 degrees C, less than 20 h at room temperature and for 51 h at refrigerator temperature. ADAM-12 levels are not altered following three - 20 degrees C to room temperature freeze-thaw cycles. The stability of ADAM-12 in whole blood appears similar to that in serum.

CONCLUSIONS

The findings of this study suggest that ADAM-12 may be unstable under many routine laboratory conditions, and the marker's instability may also be partly responsible for the discrepancies in the literature.