Risk of viral contamination is one of major concerns common to all biologics derived from cultivated cells. Bovine viral diarrhoea virus (BVDV) has widely been known as a contaminant of cell culture-derived vaccines. The objective of the study was to assess the limit of detection and range of quantitation of the detection methods for BVDV using a reverse transcription-polymerase chain reaction (RT-PCR) assay, real-time RT-PCR assay, and RT-PCR-ELISA. One milliliter of cell culture supernatant containing $10^{6.5{pm}0.2}$ median tissue culture infectious dose ($TCID_{50}$)/ml of BVDV NADL strain was subjected to RNA isolation. The isolated RNA was 10-fold serially diluted and each diluted sample ($10^{-1};to;10^{-6}$) was subjected to RT-PCR on a $GeneAmp^{(R)}$ PCR System 9700 and/or $LightCycler^{TM}$. The amplified products were analyzedly (1) agarose gel electrophoresis for RT-PCR assay, (2) melting curve analysis for real-time RT-PCR assay (in this case a program is automatically linked to amplification step), and (3) ELISA using capture and detection probes for RT-PCR-ELISA. The limit of detection of the 3 assay methods was equally estimated to be 316 $TCID_{50}/ml$ of starting virus culture supernatant subjected to the assay. The quantitation range of real-time RT-PCR assay and RT-PCR-ELISA was estimated to be from $3.16{ imes}10^5$ to $3.16{ imes}10^2$ $TCID_{50}/ml$ of starting virus culture supernatant. The overall results suggested that the 3 assay methods for BVDV detection can be reliably applied to evaluate BVDV contamination in biologics derived from cell cultures.