There are very few risks to donating your samples for research. The greatest risk is the accidental release of information from your health records. The chances that your information will be released outside the biobank are very small. There are security measures designed to prevent this from happening.
You may be uncomfortable with the fact that the biobank will not contact you before your samples are selected for research studies. If, because of your religious or other beliefs, you would not want your samples to be used for certain types of research, donation may not be right for you.
Your doctor or nurse will prepare you for any physical side affects you may have from having a medical procedure, such as bruising or soreness at the place where your samples are taken.