Hi, I'm looking for some information on retrospective consent for additional research samples. Say for example the main study consent has been signed but the patient has forgotten to sign the additional research consent form but an extra sample has been taken, is it possible to isolate this one sample until retrospective consent can be taken within a short time frame? Is it more ethical to do this or to destroy the sample and consent at the next visit and re-take the sample? I would love to hear everyone's thoughts on this. Thanks.