Table 1.

Comparison of sensitivity and limitations of conventional viral detection systems.

Detection System	Sensitivity (TCID50)	Limitations
ELISA	105	Requires multiple sampling steps and reagents
PCR	5–100	Requires parallel testing of external standards, complex multistep manipulations [e.g., labor-intensive sample preparation (plasma separation and RNA extraction), amplification (expensive reagents), and detection]
Cell Culture	104	Requires skilled technicians, time-consuming and costly. Some viruses cannot be cultured