We do recommend collecting your sample in the morning between Monday and Thursday so that your sample arrives at the lab in good time. If you are sending any samples on a Friday, we would recommend purchasing guaranteed next day delivery at the post office. This will then ensure your sample arrives at the laboratory on the Saturday. Please note that we cannot accept responsibility for samples arriving at the lab too late for them to be processed, if this does happen, we will be in contact with you to discuss options and offer another test if necessary.