E.Coli derived camelid antibodies as a sensor for P53 in saliva

Oral squamous cell carcinoma (OSCC) is a malignant tumor with 640,000 new cases annually in the world [1]. Saliva testing is non-invasive procedure that is capable to detect potential biomarkers for OSCC. It was shown that elevated level of p53 protein was identified in OSCC patients at different stages of the disease (ibid). Camelid antibodies containing only variable regions, nanobodies (VHH) and single-chain variable regions (scFv) with VH and VL, are becoming popular in many biological studies including diagnostic applications. It was identified that VL region alone showed higher affinity to p53 than VHH, and dimerization of VL region with another one increases the affinity up to 10 folds [2]. Camelid antibodies have similar affinity to its substrate as human antibodies and can be conjugated to other proteins without functional lose. They can be expressed and secreted in many organisms including E.Coli in high amount, which reduces the cost of antibodies production. Thus, the aim of this project is to design a biosensor, based on available sequence of antibodies, to detect p53 in saliva samples for OSCC diagnosis

Reproducibility of fluorescent expression from engineered biological constructs in E. coli

We present results of the first large-scale interlaboratory study carried out in synthetic biology, as part of the 2014 and 2015 International Genetically Engineered Machine (iGEM) competitions. Participants at 88 institutions around the world measured fluorescence from three engineered constitutive constructs in E. coli. Few participants were able to measure absolute fluorescence, so data was analyzed in terms of ratios. Precision was strongly related to fluorescent strength, ranging from 1.54-fold standard deviation for the ratio between strong promoters to 5.75-fold for the ratio between the strongest and weakest promoter, and while host strain did not affect expression ratios, choice of instrument did. This result shows that high quantitative precision and reproducibility of results is possible, while at the same time indicating areas needing improved laboratory practices.Peer reviewe