Comparison of two highly automated DNA extraction systems for quantifying Epstein-Barr virus in whole blood.
BACKGROUND
Optimal automated molecular methods are needed to monitor Epstein-Barr virus (EBV) infections in transplant recipients.


OBJECTIVE
To compare the extraction of EBV DNA from whole blood using the COBAS Ampliprep and the MagNA Pure instruments (Roche) for quantifying EBV DNA by real-time PCR.


METHODS
EBV DNA content was determined on clinical samples extracted by both systems.


RESULTS
The detection limit was 2.16log(10)copies/mL using the COBAS Ampliprep extraction system. Specificity was 100% and we saw no cross-contamination. Extraction was linear from 2.60 to 5.60log(10)copies/mL. The intra-assay variation was 1.91% for 3.60, 2% for 4.60 and 4.51% for 5.60log(10)copies/mL; inter-assay variation was 4.88%. Sixty-six samples were tested: 26 were positive and 28 were negative by both methods. One sample was MagNA Pure positive/COBAS Ampliprep negative (virus load 3.15log(10)copies/mL) and 10 samples were MagNA Pure negative/COBAS Ampliprep positive (virus loads from 1.59 to 3.51log(10)copies/mL) (P<0.0001). Both methods gave similar quantitative results (average difference 0.07log(10)copies/mL) which were well correlated (r=0.73, P<0.001).


CONCLUSIONS
The COBAS Ampliprep extraction system is comparable to the MagNA Pure and offers a high reliability for extracting EBV DNA from whole blood.
Mengelle
C
C
Department of Virology, CH Toulouse, France. mengelle.c@chu-toulouse.fr
Legrand-Abravanel
F
F
Mansuy
J-M
JM
Barthe
C
C
Da Silva
I
I
Izopet
J
J
D001331:Automation; D004279:DNA, Viral / Q000097:blood*; D020031:Epstein-Barr Virus Infections / Q000821:virology*; D004854:Herpesvirus 4, Human / Q000302:isolation & purification*; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019562:Viral Load / Q000379:methods*
D004279:DNA, Viral