Difference between revisions of "Team:IISER-Mohali-INDIA/Circuit"

The quest began with the search for ways to curb the problem to capture as well as detection of noxious gases and harmful chemicals. The task was to make a circuit with feedback positive and negative loops for increasing the sensitivity and specificity of detection. We came up with a novel circuit that can be modified easily for detection of various pollutants. Some pollutants activate a promoter whereas others repress a promoter. For eg: CO activates the COOA promoter whereas Acetaldehyde represses XylR promoter. The circuit we have designed can be used for both kinds of pollutants

Circuit 1 represents the circuit for activator whereas Circuit 2 represents circuit for repressor type pollutant.

Ciruit 1

Different pollutants can be used with their activating circuits having respective promoters to replace module 3 appropriately. Examples of pollutants acting as positive regulators include CO, Xylene, NO etc.

Ciruit 2

Different pollutants that can negatively regulate respective promoters can replace first part of module 3 appropriately.

Circuit can be divided into 3 parts. The bottom circuit gives a color when there is no pollutant. It signifies the number of cells alive and with an ability to form chromoprotein. In the presence of pollutant, the topmost part detects the pollutant and activates the formation of second chromoprotein in the middle circuit. Simultaneously, it inhibits the production of first chromoprotein. This results in the differential color formation depending upon the concentration of pollutant [1]. It has been documented that positive feedback has a stabilising effect on circuit. Also, negative feedback loops makes a system robust against alterations and noise [1].

Reference:

1. Cinquin, O., & Demongeot, J. (2002). Roles of positive and negative feedback in biological systems. Comptes rendus biologies, 325(11), 1085-1095.