BCH4160/2011:Notebook/Tiffany Byerly Biochemistry Lab/Methyl Red Lab

From OpenWetWare

Jump to: navigation, search
BCH4160/2011: Biophysical and Bioanalytical Lab at HPU

Home        People        Materials        Protocols & Lab Reports        Help       

Overview

Determine the pKa of methyl red by measuring the UV/Vis absorbance spectrum as a function of pH

Materials

  • Methyl Red solution provided by instructor
  • Buffer Components
    • Phosphate/Citrate buffer pH 4.0, 4.23, 5.16, 6.0, 6.7, 7.16, and 7.40
  • OceanOptics UV/Vis sprectrophotometer


Procedure

  1. Prepare 7 mM buffers at pH 4.0, 4.23, 5.16, 6.0, 6.7, 7.16, and 7.40
    • I used Phosphate/Citrate buffer
  2. Determine the optimal concentration of Methyl Red solution diluted into buffer to give a maximum absorbance between 0.7 and 1.0.
    1. Dilute 150μL methyl red solution with buffers at pH 4.0, 4.23, 5.16, 6.0, 6.7, 7.16, and 7.40 to a final volume of 1.00 mL
    2. Measure the full absorbance spectra
    3. Choose methyl red concentration for spectral measurements
      • Repeat 3 times
Personal tools