Blood samples and high-throughput sequencing
How genes turn into an object of research
Although visiting study participants who are close to 100 years of age, sociologist Sonja Boerm and study nurse Kerstin Milbradt rarely see retirement or nursing homes. Most of the study participants still live in their own homes. One 96-year old lady even suggested a meeting during her weekly tennis match.
Luise V. welcomes Sonja Boerm and Kerstin Milbradt in the bicycle shop of a small town in northern Schleswig-Holstein. The 98-year old founded the business after the end of World War II and managed it until a few years ago. Today her grandchildren run the business. Still, Luise V. visits the shop daily. "The only no-go area is the computer. The young people are always afraid that something “crashes” as they call it", she smilingly admits on her way to lunch.
During her lunch break Luise V. talks to Sonja Boerm and Kerstin Milbrandt. She patiently answers the sociologist's questions about her long life and passes physical and concentration tests with flying colours. At the end of their meeting, Kerstin Milbradt takes a blood sample from the sprightly old lady.
The threesome of healthy ageing: environment, living conditions and genes
Back in Kiel, the questionnaire on Luise V.‘s life is evaluated. Today, it is assumed that living conditions also influence the ageing process, as do environmental factors. And then there is the genetic disposition, on which scientists worldwide currently focus.
The Research Group for Healthy Ageing is already working on the identification of longevity genes and/or genes that are thought to be responsible for life-shortening diseases such as cancer, stroke or diabetes.
The protection of privacy: No correlation between study participant and blood sample
Kerstin Milbradt hands the blood to the institute’s laboratory after completely anonymising the sample. Work with genetic material is highly sensitive and tightly controlled by the data protection agency.
The scientists do not even need this correlation, for that matter. What they need is the genetic material only, the DNA from the nuclei of the white blood cells.
For the researchers to receive this, Ilona Urbach and her fellow lab technicians of the "Intake" laboratory have to extract the genetic material from the blood. Processing the sample using heat, chemicals, saline solutions and a centrifuge make the cells release their DNA. At the end, a whitish, transparent substance floats through test tube.
For the DNA extraction, he lab technicians only need a small amount of the blood sample. The remaining blood of the precious samples is archived in the biobank, a number of voluminous freezers in which blood samples of remarkably long-lived individuals are stored.
Genetics - or how to read four-letter words
Now the DNA of Luise V. - and 3,000 other long-lived individuals – can be analysed. The bioinformaticians of the institute have programmed powerful analysing robots to do exactly that. Chief scientist Almut Nebel and her team are looking for genes or their variants which could influence life expectancy. The high-tech machines can analyse hundreds of samples in one run.
The robots provide the scientists with endless columns composed of the letters T, A, G and C, since the genome consists of the chemical components thymine, adenine, guanine and cytosine. Almut Nebel and her colleagues Friederike Flachsbart and Rabea Keindorp meticulously study the deceivingly simple genetic codes for letter combinations which could contain hidden messages. Perhaps those letter codes contain construction plans for special proteins that trigger unusual signal pathways, or they encrypt an exceptional biochemical command. Maybe one that explains why in the arteries of some people more plaques are deposited than in others or which is extremely efficient in dealing with free radicals.
Almut Nebel, Friderieke Flachsbart und Rabea Kleindorp will keep decoding those four-letter combinations until they have identified the genes that contribute to the long and healthy lives of Luise V. and her peers.
