Exhibit 31.1

Certification Pursuant to Section 240.13a-14 or 240.15d-14
of the Securities Exchange Act of 1934, as amended

I, Henry E. Blair, certify that:

1.	I have reviewed this Amendment No. 1 to the annual report on Form 10-K of Dyax Corp.; and

2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.