Print-out

The underlying math governing the distribution of colonies in a specific geometry is simple enough to encode on a piece of paper.Ìý To use this approach, just line up the colony-containing pipette tips with a printed ruler with markings specifying the expected position of a particular colony.Ìý The compiled Matlab App below can be used to generate rulersÌýfor cones with arbitrary lengths and volumes.Ìý Colony counting never looked so easy on paper.Ìý ÌýÌý

Ìý GVA Homepage

The best way to get the hang of GVA is to try it out for yourself. Browse some of our datasets to troubleshoot your code before applying GVA to your own experiments.

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How to do GVA on Paper

An ideal approach for field data, low resource settings,Ìýor STEM education, this approach estimates the number of colonies in the sample based on the position of the X colony from the tip, where X >Ìý3.Ìý The more colonies counted the more accuate the result, but with diminishing improvements.Ìý In general finding the position of the 10th colony is sufficient to usually be within a factor of 2 of the correct value.Ìý Using a magnifying glass can help increase the dynamic range by allowing the visualization of colonies too small to count by eye.

Explore Another Approach to GVA

Images tips with a high-resolution camera. The increased resolution expands your dynamic range.

*Image 12 tips at a time
~$3K to set up

Ìý Camera Protocol Ìý GVA Homepage

Uses 3D printed parts to stereotypically position tips in front of a macro lens.

*Images 1 tip at a time
~$100 (not including phone)

Ìý Smartphone Protocol Ìý GVA Homepage