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.
Clinical Biochemistry Department, Prenatal Research Unit, King George Hospital, Goodmayes IG3 8YB, UK.
N J
NJ
Cowans
A
A
Stamatopoulou
S
S
Jaakohuhta
K
K
Spencer
D051722:ADAM Proteins / Q000097:blood / Q000378:metabolism*; D000072199:ADAM12 Protein; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001800:Blood Specimen Collection / Q000379:methods / Q000592:standards; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis; D005189:False Positive Reactions; D005260:Female; D005865:Gestational Age; D006801:Humans; D008565:Membrane Proteins / Q000097:blood / Q000378:metabolism*; D009035:Mothers; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood* / Q000378:metabolism; D011262:Pregnancy Trimester, Second / Q000097:blood / Q000378:metabolism; D011296:Prenatal Diagnosis / Q000379:methods / Q000592:standards; D055550:Protein Stability
D015415:Biomarkers; D008565:Membrane Proteins; D051722:ADAM Proteins; D000072199:ADAM12 Protein; C000606480:ADAM12 protein, human