PROGRESS TOWARD THE VALIDATION OF ALTERNATIVE TESTS

ECVAM's role in the practical validation of replacement alternative me thods for use in regulatory testing is reviewed, including an outline of the criteria which have been used in determining ECVAM's priorities . Some of the difficulties which have arisen in validation studies are discussed, and solutions to these are proposed, with particular empha sis on ensuring that methods are sufficiently well-developed to enter the validation process, and on the ECVAM prevalidation scheme for enco uraging protocol optimisation and the prior assessment of interlaborat ory transferability. Comments are made on problems encountered in sele cting test materials backed by adequate in vivo data and in undertakin g appropriate in vivo/in vitro comparisons.