Improved ELISA and dot‐blot methods for the detection of whey proteins in meat products

Two techniques, ELISA and dot‐blot, were applied to the qualitative detection of very low levels of whey proteins in liver pãtés. The use of an avidin‐biotin amplification system for both methods led to a useful improvement of the detection limit. The detection level which was 4 g kg−1 with the classical ELISA method was improved to I g kg−1 with the amplified ELISA method. Using the dot‐blot technique, the results showed that the minimum detectable level was 1–7 g kg−1 for the classical method with nitrocellulose (NC), 0–7 g kg−1 for the amplified method with NC, 0–7 g kg−1 for the classical method with cyanogen bromide‐activated NC (activated NC) and 0–3 g kg−1 for the amplified method with activated NC.