Team:Stockholm/8 October 2010




Birthday cake

Short day in lab - birthday celebrations!

Growth curve assay

Inoculated fresh LB with 0.3 mM IPTG with ON cultures to a startup OD of 0.2 and a total volume of 50 ml in 150 ml side-arm E-flasks.

Was advised to use a smaller cultures for the flask size. Experiment canceled after about an hour; will be repeated next week.

Removal of insertion in BioBrick suffixes

Plasmid prep

Spun down pSB1C3.SOD ON culture at 13,000 x g, 10 min. Supernatant discarded and cell pellet stored in -20 °C for later plasmid prep.


Protein purification

I performed a protein purification of SOD.His (N terminal). The pellet came from an IPTG induced 12 ml overnight culture.

Lysis buffer:

630 ul * 2 = 1260 ul lysis buffer

Wash buffer:

10X lysis buffer 12.6 ml

Elution buffer:

5X lysis buffer 6.3 ml

  • PMSF

100 * volume = 1260 * 1

12.6 ul PMSF added in lysis buffer

  • Imidazole

2 * volume = 1260 * 10*10^-3

6.3 ul imidazole added in lysis buffer

  • Imidazole

2 * volume = 1260 * 20*10^-3

126 ul imidazole added in wash buffer

  • Lysozyme

The tip of a spoon was added in lysis buffer

  • DNase

20 ug/ml was added in lysis buffer

column equilibration

The work is carried out in a cold room.

  • Ni-resin was vortexed and 1 ml was added in a drop column.
  • 5 ml wash buffer was added and run through the column (to equilibrate the Ni-resin).
  • The lysis mixed with the bacteria pellet was added in the column. However, the mixture seemed to plug the column and nothing could run through.

I left this in the cold room over the weekend to check with anyone at the department what to do and if I still can work with this material.


SOD activity assay

  • Searching "web of science" for SOD activity assays
SOD activity.png

  • Generates O2-
    • Xanthine + xanthine oxidase
    • NADH + phenazine methosulphate
    • riboflavin + methionine

  • Reacts with O2- and can be measured
    • cytochrome C
    • nitro-blue tetrazodium NBT
    • adrenaline
    • pyrogallol
    • hydroxylamine

  • Catalase-like test?
    • No, since E. coli are catalase positive and SOD differences will not be detectable

  • SOD activity test that chemically produces O2-
graded levels of SOD  ?
  • Incubate in RT, darkness for 10min
  • Measure A540
  • negative control = without NADH
NBT 1mg
phenazine methosulphate 10µg
gelatin 1mg
phosphate 0.1M
NADH 1mM 0.1ml
tot 3ml

The Faculty of Science at Stockholm University Swedish Vitiligo association (Svenska Vitiligoförbundet) Geneious Fermentas/ Sigma-Aldrich/