STEM Electrophoresis with Food Dyes Bio-Rad Biotechnology Explorer IDEA and STEM Kits

Materials to be Separated Property Used to Separate Components Separation technology: How do you separate two or more compounds from each other? Materials to be Separated Property Used to Separate Components Explanation Iron filings from other metals Magnetism Iron filings will be attracted to a magnet while other metals will not Salt from sand Solubility Salt will dissolve in water and can be separated from the sand Caffeine from coffee beans A solvent is used that selectively dissolves the caffeine (such as dichloromethane or ethyl acetate) but not most of the remaining coffee oils Ethanol from fermented grain Boiling point Ethanol will boil off at a lower temperature than the other components of the fermented grain Wheat from chaff Density Wheat kernels are more dense and will fall to the ground while chaff can be blow away by the wind Tea from tea leaves Size Filtration can be used to separate the liquid extract from the large tea leaves

Electricity can be used to separate molecules by charge Acetate ions Tris ions - HO CH2 C CH2 OH NH3+ CH2 OH + CH3 C O O- + - Apply an electrical charge

Sieves can be used to separate materials by their size

Electrophoresis separates molecules by CHARGE and SIZE Electrophoresis means “to carry with electricity” Molecular sieve Electricity

Food dyes – What have you recently eaten?… Did you eat any cheddar cheese? Was it orange? Starbucks Strawberry Frapuccino?

FD&C Dyes and Natural dyes FD&C Synthetic Dyes FD&C Red 40 or FD&C Red 40 Lake FD&C Yellow 6 or FD&C Yellow 6 Lake FD&C Yellow 5 or FD&C Yellow 5 Lake FD&C Blue 1 or FD&C Blue 1 Lake FD&C Blue 2 or FD&C Blue 2 Lake FD&C Red 3 or FD&C Red 3 Lake FD&C Green 3 or FD&C Green 3 Lake Natural Dyes Beetroot red or betanin (from beets) Curcumin (from tumeric) Caramel coloring (from sugar) Annatto (seeds of achiote trees) Carminic acid, carmine, or cochineal (from ground up beetle abdomens) Lycopene (from tomatoes, watermelons, papayas, and red carrots)

Food dyes in the news

Food dyes have an intrinsic SIZE and CHARGE and thus can be separated using Electrophoresis Molecular weight Charge FD&C Blue 1 792.86 -2 FD&C Yellow 5 534.37 -3 FD&C Yellow 6 452.37 FD&C Red 40 496.43 Carminic Acid 492.38 Beetroot red 551.48 +1

So how do we design an electrophoresis chamber to separate food dyes? Dye Electrophoresis Commercial versus built box comparisons

What are some of the design factors we want to think about?

Building and running your electrophoresis system to separate the dyes

Building and running your electrophoresis system to separate the dyes

Building and running your electrophoresis system to separate the dyes

Building and running your electrophoresis system to separate the dyes

Building and running your electrophoresis system to separate the dyes

Extensions Copper electrode Electrochemistry study pH changes at the cathode and anode Effect of material choice for electrode Optimization of STEM box system Electrode material choice and thickness Different materials for gel thickness Impact of TAE Concentration and Volume Gel percentages Gelatin matrix