Why test blood? 
Blood is made up of several components including plasma and several types of cells. Separating blood into its component parts allows us to look at molecules called biomarkers.

Why test DNA? 
The DNA (deoxyribonucleic acid) sequence is the material that is found in our genes. DNA is remarkably similar from one person to the next, but tiny variations do occur, rendering each of us a unique individual. Most of these changes in our genes are harmless and cause such variation as eye colour and height. There can also be changes in genes that cause them not to work properly and lead to eye problems or disease. We will also look at other factors that influence gene expression and this is referred to “epigenetics”.