Stable composition containing NAD+ or NADH

[0023] Application of the present invention in lactate dehydrogenase test kit:

[0024] First prepare kit reagent 1: 40 mmol / l lactic acid, 100 mmol / l Tris solution, adjust pH to 9.2 with 1 mol / l hydrochloric acid or sodium hydroxide.

[0025] Re-preparation kit reagent 2: containing trehalose 10g / l, glycerol 1g / l, Tris 0.1mol / l, Tween 20 0.1g / l solution, then use 1mol / l hydrochloric acid or sodium hydroxide to adjust its pH to 7.0, then weigh some NAD + Dissolve in 10ml of the above protective agent to make the concentration reach 20g / l, and stir evenly.

[0026] The above-mentioned reagent 1 and reagent 2 constitute the lactate dehydrogenase kit, and the storage period of this kit can reach 18 months at 2-8°C. Through comparative experiments, the lactate dehydrogenase kit without stabilizers can only be kept for twelve months under the same conditions.

[0028] Application of the present invention in α-hydroxybutyrate dehydrogenase kit:

[0029] First prepare the kit reagent 1: a solution containing trehalose 5g / l, glycerol 10g / l, Tris 0.1mol / l, Tween 20 0.5g / l, then adjust its pH to 7.0, then weigh 10mg NAD and dissolve it in 10ml of the above protective agent, stir evenly.

[0030] Reconstitute kit reagent 2: nitric acid 50mmol / l solution, α-oxobutyric acid 3mmol / l. Adjust the pH to 7.5.

[0031] The above-mentioned reagent 1 and reagent 2 constitute the α-hydroxybutyrate dehydrogenase kit, and the storage period of this kit can reach 18 months at 2-8°C. Through comparative experiments, the lactate dehydrogenase kit without stabilizers can only be kept for twelve months under the same conditions.