Fig. 6From: Hydroxymethylbilane synthase (HMBS) gene-based endogenous internal control for avian speciesInfluence of swabbing technique and HMBS and AIV copy numbers in experimentally infected chickens. Thorough swabbing resulted in the highest HMBS positivity and copy number, and the highest AIV positivity. In strong contrast, the swabs collected with gentle swabbing had the lowest HMBS positivity and copy number, with none being positive for AIVBack to article page