BME494 Sp2014 Tran
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Background & Proposed ApplicationBACKGROUND
The malarial biosensor is modeled after the classical synthetic toggle switch developed in Escherichia coli, or E. Coli (Gardner et al 2000). The precedent synthetic system was developed with two different inducible states, an “on” and “off” state. The system was created using two promoter and repressor pairs. Both repressors were inhibited by a different inducer (aTc and IPTG). The promoters were placed upstream of the repressor gene of the opposite pair. This created a bistable system where only one promoter would be expressed at any one time, since the expression of a promoter repressed expression of the other promoter. To distinguish a cell between its on state and off state, a green fluorescence protein transcription gene was placed downstream of the on state promoter so the cell would exhibit green fluorescence in its on state. 
Malaria is a disease caused by any one of five different species of plasmodium, including P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowles. The life cycle of these plasmodium consist three different phase. During one phase, the plasmodium reproduces within a female mosquito. When the mosquito takes a blood meal from a human, the saliva of the mosquito, abundant with the pathogen, transfers the disease into the new human host. From there, the parasite infects and multiplies inside of liver and blood cells. The World Health Organization estimated that malaria was responsible for approximately 207 million clinical episodes and more than 600,000 deaths. More than 90% of fatal cases of malaria originate in Africa. Malaria presents itself with fever, sweats, chills, and other symptoms commonly associated with a common cold. When discovered early, malaria has a low mortality rate and can be readily treated. Unfortunately, because malarial symptoms can be difficult to recognize, diagnosing malaria can often be an arduous task. Currently, the most widely and accepted standard for diagnosis consists of microsopy. Microscopy techniques consist of taking a drop of a patient’s blood and staining it with a dye that gives plasmodium a distinct appearance. The drop is then examined under microscope for the presence of these dyed plasmodium. Microscopy is the most reliable method of diagnosis but requires quality reagents, microscopes, and an experienced lab technician. Generally, microscopy requires travel to an apt-equipped facility with the proper equipment which is not always a possibility. Another widely used method of diagnoses is Rapid Diagnostic Tests (RDTs). RDTs test a patient's blood for the presence of malaria related antigens. The fallback to RDTs though are they still need to be improved for accuracy, often require the use of a clinician, and can be costly. The proposed device hopes to remedy the problem of diagnosing malaria in remote areas and rural communities which do not have access to advanced tools such as microscopes. If successful, the device will be placed into small kits which would be used to test a drop of the patient’s blood and results would be readable within the day. The kit would designed to be easy to use so rural communities without experienced clinicians could still have a preliminary means of diagnosing malaria.
Design of a New Device
Building the New DeviceSYNTHETIC DNA LAYOUT
Testing the New DeviceLAC OPERON MODEL SIMULATION
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