Bio ArtBot

 Recently, I joined the Counter Culture Lab in Oakland CA as an intern.  It is a rather interesting maker space for bio hackery.  My mentor has assigned me to the Bio ArtBot project where I can pickup some basic lab skills.  I am working on transforming e-coli bacteria with plasmid gene which expresses color.  The competant cell we are using is call the DH5-alpha from NEB (New England BioLabs Inc).  The product number is C2988J which costs $73 to buy as of 2022.

Here is a sample transformation protocol:

1. Thaw a tube of NEB 5-alpha Competent E. coli cells on ice until the last ice crystals disappear. Mix gently and carefully pipette 50 µl of cells into a transformation tube on ice.
2. Add 1-5 µl containing 100 pg-1 µg of plasmid DNA to the cell mixture. Carefully flick the tube 4-5 times to mix cells and DNA. Do not vortex.
3. Place the mixture on ice for 30 minutes. Do not mix.
4. Heat shock at exactly 42°C for exactly 30 seconds. Do not mix.
5. Place on ice for 5 minutes. Do not mix.
6. Pipette 950 µl of room temperature SOC into the mixture.
7. Place at 37°C for 60 minutes. Shake vigorously (250 rpm) or rotate.
8. Warm selection plates to 37°C.
9. Mix the cells thoroughly by flicking the tube and inverting, then perform several 10-fold serial dilutions in SOC.
10. Spread 50-100 µl of each dilution onto a selection plate and incubate overnight at 37°C. Alternatively, incubate at 30°C for 24-36 hours or 25°C for 48 hours.

The above protocol is also available from the product page.

It turned out Counter Culture Lab got the dry DNS from freegenes.org.  These DNS also can be cultivated in the lab and stored for later use.  Usually the lab would have extra reporter DNSs for regular usage.  The freegenes.org has some fluorescent reporter and some colorimetric reporter.  The gene name usually tells which reporter metric for example for gene name with GFP designation, it means green fluorescent protein (GFP).  Other color variants cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) also exist.   For none fluorescent color metric, the color name is part of the gene name.  Reporter signal amplifier also exists.  Where assay is done instruments rather than naked eye, there are reporter genes for spectrophotometric as well.