Recipes
DTT-Based Reduction Solution for Karatin Extraction

DTT-Based Reduction Solution for Karatin Extraction

Preparation

Target volume

Unit

Step 1. Add distilled water into an approprialty sized L beaker.

distilled water

87.5 mL

Step 2. Add urea slowly to water while stirring.

Urea

10 g

Step 3. Stir manually for 2–3 minutes until dissolved

CAUTION: 10N NaOH is extremely caustic — handle with care, work in fume hood, wear gloves and goggles CAUTION: Still exothermic even as a solution — add slowly to prevent splashingly to the urea solution over 1–2 minutes while stirring.

Step 4. Measure 10M NaOH using a graduated cylinder.

10M NaOH

12.5 mL

Step 5. Add slowly to the urea solution over 1–2 minutes while stirring.

Step 6. Stir gently until fully mixed (~2 minutes). Temperature will rise to 30–40°C (normal; do NOT use ice-cooling)

Step 7. Reduce stirring. Allow to sit for 10–15 minutes at room temperature.

Step 8. Add L-Cysteine powder slowly over 1 minute while stirring at 200 rpm.

L-Cysteine Hydrochloride

1.6 g

Step 9. Stir for 3–5 minutes until well-integrated. Solution should remain clear to light amber.

Step 10. Add DTT powder slowly over 30 seconds while stirring at 200 rpm

DTT

1 g

Step 11. Stir for 2–3 minutes until fully dissolved.

Nested recipe inputs

Used in step 5

Target volume

Unit

Step 1. Prepare an ice bath before starting — this reaction generates substantial heat

Step 2. Add approximately 500 mL distilled water to a 2 L beaker sitting in the ice bath.

Step 3. Slowly add NaOH pellets in small portions to the water — never add water to pellets

Sodium Hydroxide

400 g

Step 4. Stir constantly between additions — allow each portion to dissolve before adding more.

Step 5. Keep beaker in ice bath throughout — solution will reach 80–90°C without cooling.

Step 6. Once all pellets are dissolved and solution has cooled to room temperature, transfer to a 1 L volumetric flask.

Step 7. Bring to final volume with distilled water, mix thoroughly, and trasnfer to a polyethylene or polypropylene bottle.

Step 8. Bring final volume to 1000 mL with distilled water.