Category Archives: DDW1

Starter Cultures in D2O, DDW, and DI Water

Based on the results from yesterday I’ll be carrying out the next phase of the experiment. I set up starter cultures to grow in DDW, DI water, and D2O so I can do hourly time points tomorrow starting early and hopefully getting about 7 hours of data (instead of 5 like yesterday).

I had grown yeast on solid media yesterday and got a bunch of colonies today, so I plucked three colonies and inoculated them in the liquid media stated above (YPD broth).

Yeast Growth Trial 1 Data

Here is the data courtesy of figshare:

S. cerevisiae growth in DI Water, DDW, 50% D2O, and 90% D2O. Anthony Salvagno. Figshare.
Retrieved 22:01, May 22, 2012 (GMT)

I would say this data is pretty exciting. Unlike the E. coli data (which was all over the place), there is a clear difference in growth rates between the D2O samples and the H2O samples. Also the growth between the DDW and DI (the H2O samples) were almost identical! That’s pretty solid.

Yeast Growth in D2O, DDW, and DI YPD: Setup

Yesterday I created a starter colony of yeast from the lyophilized yeast that I ordered from Today I’m doing growth in different water types and checking the growth every hour just like the e. coli experiments. Here is my setup:

  1. Make YPD broth with DDW and D2O.
    1. the bottles of both come in 100g quantities which means there is 90-ish ml of D2O and 100-ish ml of DDW
    2. I had 91ml of D2O –> 4.55g of YPD powder
    3. 100ml of DDW –> 5g of YPD powder
  2. suspend powder in water types and filter via syringe. DO NOT AUTOCLAVE
    1. the reason is because of deuterium exchange. The powder is ultrapure and the water is pretty pure itself, so filtering should be just fine.
  3. To make diluted cultures:
    1. I have 4 samples: 1) DI water 2) DDW 3) D2O and 4) 50% D2O in 50% DI water
    2. Put 9ml of each water type into a test tube (except for the 50/50 mix which should be 5ml of d2o and 4ml of di water)
    3. Add 1ml of starter culture (which is made from DI water)
    4. put in incubator
  4. take time points every hour in semi-micro cuvettes using nanodrop. I fill them with 0.5ml of each culture.