Media formula

TAP (Tris-Acetate Phosphate)

To make one liter of TAP:

• 10 mL 2M Tris-acetate (pH 7.0)
• 10 mL Phosphate buffer (pH 7.0)
• 10 mL nutrient stock
• 10 mL trace metals (10x dilution)
• Bring to 1 liter with distilled water

Variations

• For plates add 15g agar per liter (1.5%)
• For TAP-sulfur substitute MgCl₂ for the MgSO₄ in the nutrient stock and omit trace metals

Materials

2M Tris-acetate stock

• 242 g Tris base
• Dissolve in 600 mL water while titrating to pH 7.0 with glacial acetic acid.
• Bring to 1 liter

Phosphate buffer

• 10.8 g K₂HPO₄
• 5.6 g KH₂PO₄
• Bring to 1 liter

Nutrient stock

• 40 g NH₄Cl
• 10 g MgSO₄·7H₂O
• 5 g CaCl₂·2H₂O
• Bring to 1 liter

Trace metals

Making this is a complex proceedure so (unless you think you will be using a lot of it) there are a couple of alternatives.

• Make a soil extract by shaking a few grams of soil in water
• Use a small amount of Job's plant food spike
• Use tap water rather than distilled.

This makes a liter of full-strength, enough for 1000 L of TAP. Dilute an aliquot tenfold and use the diluted stock in making TAP

1. Dissolve 50g of acid free EDTA in 250 ml of ddH₂O. Heat to dissolve.
2. Dissolve the following, one by one, in order, heating to approximately 100° in 550 ml ddH₂O.
   • 11.40 g BO₃H₃
   • 22.00 g ZnSO₄·7H₂O
   • 5.06 g MnCl₂·4H₂O
   • 4.99 g FeSO₄·7H₂O
   • 1.61 g CoCl₂·6H₂O
   • 1.57 g CuSO₄·5H₂O
   • 1.1 g Mo₇O₂₄(NH₄)₆·4H₂O (Ammonium Molybdate)
3. Mix the two solutions (1 & 2) together. The resulting solution should be blue-green.
4. Heat to 100°C. Cool slightly, but don't let the temperature drop below 80°-90°.
5. Adjust pH to 6.5 to 6.8 with 20% KOH (approximately 83 ml). Don't let the temperature drop below 70° until after the pH is adjusted.
6. Make up to 1L and let stand in a 2L Erlenmeyer flask, stoppered loosly. The color should change from green to purple over a period of days.
7. Remove the rust-coloured precipitate by filtering, with suction, through 3 layers of Whatman #1 filter paper in a Buchner funnel. Repeat until no more precipitate is seen on the filter paper
8. Store in a brown bottle at 4°.

Links

Recipe taken from: http://www.chlamyteach.info/growthmedium.html