Meet Dr. Karin Söderlund, sports scientist at the Swedish School of Sport and Health Sciences (GIH) in Stockholm.

Students and other healthy volunteers are participating in different research programs at the Swedish School of Sport and Health Sciences in Stockholm. One area of research is to optimize diet and exercise with the ultimate aim of increasing performance. One of the researchers is Dr. Karin Söderlund who studies ATP and phosphocreatine levels in isolated muscle fibers. She also investigates how diseases such as Chronic Obstructive Pulmonary Disease (COPD) affect muscle fiber metabolism.

Dr. Karin Söderlund in her laboratory

Different types of muscle fibres have different sorts of metabolism, and Karin looks at how exercise, diet and disease affect these muscle fibers. “The research group looks at how a sportsperson should plan their exercise and how much carbohydrate and protein their muscles use during exercise” says Karin, who has been using BioThema’s kits for measuring ATP levels for many years.

The tiny muscle fibres are handled with insect needles.

The preparation of the samples is a crucial step. A small biopsy is taken from the thigh of the human test subject, about 200 mg of muscle (about the size of a pea). The sample is freeze dried to make the separation of the individual muscle fibres easier, which is done mechanically using a microscope. Muscle fibres can be either “fast” or “slow” (slow muscle fibers are more fatigue resistant then fast twitch fibers) and to determine which type the fibers are, they are stained using a special dye. The individual muscle fibers are tiny weighing  between 1-4  µg, and to be able to weigh them Karin has built a fishpole balance.

Karin using the specially built fishpole-balance for measuring individual muscle fibres.

“The ATP assay has worked extremely well and we are very happy with the quality of the products and the technical support from BioThema ” says Karin who has published more than 10 papers based on the measurement of ATP and creatine phosphate in muscle fibers. Her laboratory is one of the leading centers for this type of research, and researchers from all over the world come to the Swedish School of Sport and Health Sciences, to learn how to do these types of measurements using ATP technology from BioThema.

Karin Söderlund can be contacted at karin.soderlund(at)

Visit www.gih. se  for more information about the research by Karin Söderlund and her colleagues.

Publications by Karin Soderlund