Table 3.

Detection of Alexandrium DNA in gill tissue samples from challenged Mytilus through days 2 to 27 by q-PCR.

Sample	Challenge periods (days)	Ct
1	2a	21.0
2	3a	21.2
3	4a	21.1
4	5a	22.0
5	15b	NA

Mytilus were exposed to a contaminated diet (1.7–2.0 mg L⁻¹; dry weight) containing 50 % toxic dinoflagellate Alexandrium strain ACC02 and 50 % I. galbana (by weight) for a period of 12 days, followed by a detoxification period of 15 days, where they were fed with I. galbana. Animals were dissected alive on Days 2, 3, 4 and 5 of the toxic phase and Day 15 of the detoxification phase, and 30 g of drained gill tissue were used as the starting material for DNA purification with the DNeasy Blood & Tissue Kit (Qiagen) according to the manufacturer's protocol. Real-time PCR assays using species-specific A. tamarense primers were carried out in extracted DNA from Mytilus in order to determine the possibility of detecting Alexandrium DNA in challenged mussel tissue. NA, no amplification.

^aDays in toxic phase.

^bDays in detoxification phase.