Quiz On Laboratory Notebook Page

Can you find all the errors on this page?
Dialyzing Cytochrome c into Tetrahydrofuran
from Water		 PAM 12/12
A. Preparation of Dialysis Membrane

Wearing gloves I cut six five-inch long pieces of dialysis membrane and rinsed these thoroughly with tap water. Afterward, I placed the six pieces in a 300-mL capacity glass bottle filled with distilled water. After one hour I replaced the water in the bottle with fresh distilled water and allowed the membranes to rest for one more hour. In the meantime:

B. Preparation of 0.13 mM cyt c in water

I weighed 0.02 g cyt c (Sigma Aldrich; horse heart) into a 10 mL volumetric flask and added DI water to the mark. I mixed the solution using a vortex mixer and placed the flask in the cold room.

C. Dialysis of Cyt c into THF

I took one of the pieces of dialysis tubing and wearing gloves tied a knot in it. I then transferred the cyt c solution into the "bag" and tied another knot at the top. I carefully placed the bag in a beaker, filled the beaker with 50/50 THF /water and placed the beaker in the cold room so the dialysis could continue overnight. The sol'n in the bag lked good - cyt c solution clear and homogeneous.

PAM 12/13
Transferred bag to new sol'n 60/40 THF /water at 9 am. Cyt c solution clear and homogeneous. At 1 pm transferred bag to new sol'n consisting of 75/25 THF /water. Cyt c solution clear and homogeneous. At 3 pm transferred bag to 95/5 THF water, protein precipitated out of the dialysis bag. Solution cloudy and no longer homogeneous :( - not my day, huh? If at first you don't succeed... started over with fresh solution of cyt c. Dialyzing into methanol.