iGEM Bielefeld 2015

Our App

Fluorescence Quantification via Smartphone

The Problem

Fluorescence is a widely used output signal in many microbiological and biotechnological applications. Green fluorescent protein (GFP) is among the most used reporter proteins and has been used in numerous iGEM projects. Nevertheless fluorescence can barely be detected by the eye and quantification turns out to be nearly impossible.

Our Solution

We solved this problem with a smartphone App. The App determines the median of the greenvalue of a area of pixels in the sensorspot and compares it to the pixels of the negative control (the not induced sensor). If the ratio of a sample and the negative control is above a certain theshold (10%), valid biosensor signal is detected. Additionally it is checked whether the value for the positive control (drop of sfGFP) is above a certain value, thereby confirming the functionality of the biosensor. Furthermore the App displays specific information regarding the different heavymetals and date rape drugs to inform the user. For easy handling a correct positioning of the smartphone and the biosensor test strip, we designed and printed a measurement case.

A photo of our test strip generated by a typical smartphone using an ideal filter combination to detect fluorescence of sfGFP.
Screenshot of the app. It shows the pixels it took into account for the calculation in red, so the user can check, whether the pixels chosen are correct. Furthermore, it provides the values it calculated for the greeness of the spot.
The application is adapted to the box shown in the picture. The box provides the ideal environment for capturing pictures under reproducible conditions. The application will calculate whether a contamination is present and give out an list of the contaminants in the water sample.