Comparison of the Biomedica NT-proBNP Enzyme Im- munoassay and the Roche NT-proBNP Chemilumines- cence Immunoassay: Implications for the Prediction of Symptomatic and Asymptomatic Structural Heart

Leukemia 2001;15:1033–7. 14. Higuchi R, Fockler C, Dollinger G, Watson R. Kinetic PCR analysis: real-time monitoring of DNA amplification reactions. Biotechnology 1993;11:1026– 30. 15. Heid CA, Stevens J, Livak KJ, Williams PM. Real time quantitative PCR. Genome Res 1996;6:986–94. 16. Soong R, Beyser K, Basten O, Kalbe A, Rueschoff J, Tabiti K. Quantitative reverse transcription-polymerase chain reaction detection of cytokeratin 20 in noncolorectal lymph nodes. Clin Cancer Res 2001;7:3423–9. 17. Livak KJ, Schmittgen TD. Analysis of relative gene expression data using real-time quantitative PCR and the 2( CT) method. Methods 2001;25: 402–8. 18. Wolfel T, Hauer M, Klehmann E, Brichard V, Ackermann B, Knuth A, et al. Analysis of antigens recognized on human melanoma cells by A2-restricted cytolytic T lymphocytes (CTL). Int J Cancer 1993;55:237–44. 19. Zaaijer HL, Cuypers HT, Reesink HW, Winkel IN, Gerken G, Lelie PN. Reliability of polymerase chain reaction for detection of hepatitis C virus. Lancet 1993;341:722–4. 20. Noordhoek GT, van Embden JD, Kolk AH. Reliability of nucleic acid amplification for detection of Mycobacterium tuberculosis: an international collaborative quality control study among 30 laboratories. J Clin Microbiol 1996; 34:2522–5. 21. Keilholz U, Willhauck M, Rimoldi D, Brasseur F, Dummer W, Rass K, et al. Reliability of reverse transcription-polymerase chain reaction (RT-PCR)based assays for the detection of circulating tumour cells: a qualityassurance initiative of the EORTC Melanoma Cooperative Group. Eur J Cancer 1998;34:750–3. 22. Pritzker KP. Cancer biomarkers: easier said than done. Clin Chem 2002; 48:1147–50.