Of Mice and Microbes: The Science Behind Food Analysis

In general, people like to know that their food is what the label says it is. It’s a real bummer to find out that beef lasagna you just ate was actually horsemeat. Plus, there are many religious, ethical and medical reasons to be cognizant of what you eat. Someone who’s gluten intolerant and Halal probably doesn’t want a bite of that BLT.

Labels don’t always accurately reflect what is in food. So how do we confirm that we are in fact buying crab, and not whitefish with a side of Vibrio contamination?

For the most part, it comes down to separation science. Scientists and technicians use various chromatographic methods, such as gas chromatography, liquid chromatography, and mass spectrometry, to separate the complex mixture of molecules in food into individual components. By first mapping out the molecular profile of reference samples, they can then take an unknown sample and compare its profile to what it should look like. If the two don’t match up, an analyst would assume that the unknown is not what it claims to be. Continue reading

Streamlined in-gel digestion protocol using ProteaseMAX™ Surfactant, Trypsin Enhancer

In-gel tryptic digests of 1-dimensional (1-D) or 2-dimensional (2-D) acrylamide gels are commonly used in proteomics to identify unknown proteins of interest. The unknown proteins are excised from the gel, digested with trypsin then analyzed via MALDI-MS or HPLC-MS with subsequent identification via bioinformatics (1).
The basic elements of the procedure include destaining, reduction/alkylation, in-gel digestion, extraction and analysis.
Trypsin is typically the enzyme of choice for the digestion step. Recommended digestion conditions range between several hours to overnight. Following digestion, the peptides are extracted and dried. An outline of example digestion/extraction protocol is follows: Continue reading