Tyrode

Tyrode, or Tyrode's solution is a clear solution commonly used in physiological experiments. It is useful in the CHAOS lab as a medium in which to store hearts while they are undergoing experimentation, because it is fairly conductive, which is good for Electrophysiology experiments, as well as high in electrolytes, allowing the heart to continue to function as long as it is submerged in fresh Tyrode solution, despite being disconnected from the body.

Composition

Tyrode generally contains a sugar, to provide energy for the heart, magnesium, and a buffer to help maintain pH. The CHAOS lab adds some salts to the general compound, including Sodium Chloride and Potassium Chloride, as will as a bicarbonate compound, in amounts listed below. Usually, however, the solution is mostly premixed in the form of Solution A, which constitutes all of the ingredients below except for Dextrose and the Calcium Chloride, Solution B, which is solely Calcium Chloride, and the Dextrose, which is added on its own. These solutions, A and B, are kept in the refrigerator to ensure they will last longer. Note it is very important to add the dextrose last in the process, as the Tyrode solution will begin to spoil as soon as the Dextrose is added, and does not have a long shelf life after the addition of Dextrose.

Premixed Solutions:

Substance	volume required to make 2L of Tyrode
Solution A	250 mL
Distilled Water	16225 mL
Solution B	125 mL
Dextrose	2 g

Total Composition:

Substance	Concentration (g/L)
NaCl	7.2453
KCl	0.2982
MgCl2 6H2O	0.1423
NaH2PO4 H2O	0.1231
NaHCO3	2.016
CaCl2 2H2O	0.294
Dextrose	0.9908

Usage

Tyrode is used in most of the Electrophysiology experiments, particularly Optical Mapping and Microelectrode. The solution is prepared before the heart is removed, to ensure that there is a place to put the heart upon removal to ensure a continued functioning. For a for Zebrafish, generally make 100 mL of solution, and scale up volume accordingly based on size of heart.