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.
Cowans
N J
NJ
Clinical Biochemistry Department, Prenatal Research Unit, King George Hospital, Goodmayes IG3 8YB, UK.
Stamatopoulou
A
A
Jaakohuhta
S
S
Spencer
K
K
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