In vitro muscle testing

In vitro muscle testing is a method used to characterize properties of living muscle tissue after having removed the tissue from an organism. This allows more extensive and precise quantification of muscle properties than in vivo testing. In vitro muscle testing has provided the bulk of scientific knowledge on muscle structure and physiology, as well as how both relate to organismal performance. In vitro muscle testing is a method used to characterize properties of living muscle tissue after having removed the tissue from an organism. This allows more extensive and precise quantification of muscle properties than in vivo testing. In vitro muscle testing has provided the bulk of scientific knowledge on muscle structure and physiology, as well as how both relate to organismal performance. Once an appropriate animal has been selected for experimentation, whether that is for a specific locomotor function (i.e. frogs for jumping) or a specific animal strain, to answer a research question, a specific muscle is identified based on its in vivo function and fibre type distribution. Firstly, following ethical approval, and if necessary government approval, the animal is humanely euthanised. Humane methods of sacrifice differ per country, with the most appropriate method selected based on ethical approval and researcher skill level. A number of further criteria should be followed to ensure the animal is completely dead without the possibility of recovery, which includes cessation of blood flow via the removal of the heart from the circulatory system and/or complete destruction of the brain and spinal column. Following this, common measures of animal morphology are usually rapidly obtained, such as animal length, animal body mass and other biomechanical markers that may be of importance. Once collected, the animal is then prepared appropriately for the harvesting of the target muscle. In isolated muscles, these tend to be muscles of the hind limbs, such as the soleus or EDL of mammals, or the plantaris or iliotibialis of amphibians. Other muscles that have been examined under in vitro conditions include the diaphragm and the papillary muscle. For the successful isolation of skeletal muscles, specific conditions are required. The tissue should be isolated in frequently changed, chilled Ringer's solution or Krebs-Henseleit solution to ensure metabolic conditions are slowed down, hence the need for chilled dissecting medium, and to prevent the tissue from dying due to lack of substrates within the medium, hence the requirement for the solutions to be changed frequently. The dissecting solution should be continually oxygenated with the appropriate concentration of oxygen and carbon dioxide for the tissue that is being prepared. Typically, non-mammalian tissues are prepared in a gaseous solution bubbled through with 98% oxygen, 2% carbon dioxide whilst mammalian tissues in a solution bubbled through with 95% oxygen, 5% carbon dioxide. A microscope with an appropriate magnification level is required due to the dexterity required for isolation of muscles. An external, fibre optic light source is also beneficial to provide sufficient light without the emission of heat.