Corn Tetrazolium

Corn kernel showing red staining patterns from Tetrazolium testing

Corn kernel showing red staining patterns from Tetrazolium testing


The tetrazolium test is a quick test to estimate potential germination. Seed is imbibed for 16 hours as a precondition stepping to allow easier long-sectioning of seeds and to ramp up respiration and enzyme systems. Seed are long-sectioned using razor blades and the cut surface is exposed to tetrazolium (TZ) chloride salt solution, when respiration is active, the TZ combines with Hydrogen ions to form “formazan” a red insoluble pigment. The topographical staining patterns are evaluated and embryos are categorized as either viable or non-viable. Seeds exposed to freezing conditions, do require drying to below 15% seed moisture content prior to preconditioning to allow enzyme systems to be regenerated due to seed respiration.

What is Reported

A percentage of viable seed (normal staining embryos and any dormant seeds).

Value of Results

Tetrazolium is a quick estimate of germination and can be useful in determining viability of hard seeds.  When seed has a fungal colonization, such as Fusarium or Phomopsis spp., the TZ test will best estimate a treated germination test.

Agronomically Accurate Seed Testing Results

SoDak Lab's goal is to deliver fast, accurate, and diagnostic seed testing services.