Purdue/3 June 2008

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Lab Meeting

In attendance:

Craig Barcus

Jess Osbourne

Matt Herron

Dr. Jenna Rickus

Dr. Kari Clase

David Jaroch - Grad Advisor

Minutes

Discussed the possibilities of using pH determination and sugar concentrations as markers for milk spoilage. Two main points of literature research were developed, the quantification of milk spoilage other than consumer acceptance, and the existing strains of bacteria that could sense pH changes and/or sugar concentration changes.

Matt is taking the bacterial side, trying to determine if any strains exist that have that capability and sorting through the bio-bricks to see if any exist or can be created from existing ones. The metabolic pathway sensing is also part of this project.

Craig is taking on the milk quantification. A former lab member from his lab, Chad Cepeda, now works for Dean's Farms, and may provide information on solid numbers or leads to what to look for. The references on May 28th will also come of use.

Also discussed was doing a live/dead assay with bacteria and the method of immobilization we plan on using. This was discussed in the provisional patent earlier. A live/dead assay is hoped to be performed within the next two days to determine feasibility.

pH measurements are to continue, and sugar concentration assays may be added at a later date along with pH measurements to get a characteristic curve.

New instructions will be sent out to lab members who were not able to attend to search for pathways and quantitative numbers for milk spoilage.

Edited above by Craig Barcus

pH experiments with milk.

Time 8:30 AM

Sample 1: 6.69

Sample 2: 6.70

Sample 3: 6.70

Protocol for taking measurements followed from June 2, 2008 page.

Noticed an increase in pH of samples 2 and 3. Could be due to variability of the pH probe.

pH experiments with milk

Time 12:10 PM

Sample 1: 6.67

Sample 2: 6.67

Sample 3: 6.68

2 non-iGEM team members accepted the milk as drinkable.

Time 4:30 PM

Sample 1: 6.58  Noticeable curdling. Unacceptable by consumer standards.

Sample 2: 6.56  Noticeable curdling. Unacceptable by consumer standards.

Sample 3: 6.63  No Noticeable curdling. Unacceptable by consumer standards.

Will Test pH again at 5 PM to check.

Time 5:30 PM

Sample 1: 6.55  Noticeable curdling. Unacceptable by consumer standards.

Sample 2: 6.53  Noticeable curdling. Unacceptable by consumer standards.

Sample 3: 6.57  Noticeable curdling. Unacceptable by consumer standards.

Edited above by Craig Barcus