Sample Research Abstracts

Following are some sample student research abstracts developed  in the Molecular Biology Research Laboratory:

Ryan Park ‘08

On-demand DNA synthesis promises to open up a wide array of opportunities in molecular biology research, including the charting, design, and synthesis of novel proteins, genetic circuits and biochemical pathways. This potential will be unlocked through the availability of cheap, reliable, efficient de novo DNA synthesis, and the main prohibitive factor is the high error rates currently inherent to oligonucleotide synthesis (Carr, Park et al. 2004). DNA repair pathways in organisms, where error rates of DNA replication are often 1 in 1,000,000 bp or lower, present models to mimic and adapt to in vitro DNA synthesis methods. At present, the lowest numbers in DNA synthesis error rates have been 1 in 10,000 bp, offering much room for improvement (Carr, Park et al. 2004). Archaeal DNA repair pathways, interesting because no convincing candidate proteins exist for detection of DNA mismatches, are thought to rely heavily on single-stranded DNA binding proteins (SSB) (Cubeddu and White 2005). Crenarchaeal SSB is a monomer with a single oligonucleotide-binding fold, of which the sequence is similar to eukaryal Replication Protein A (RPA), coupled to a C-terminal tail reminiscent of bacterial SSB (Kerr, Wadsworth et al. 2003). I have overexpressed and purified a His-tagged version of Sulfolobus Solfataricus SSB (SsoSSB) and demonstrated ssDNA-binding activity on 39 bp oligonucleotides. I have attempted to show that SsoSSB can selectively melt duplex DNA containing a mismatch error. Based on this melting activity, I consider future applications of SsoSSB in improving the efficiency of PCR and accuracy of de novo DNA synthesis, allowing for the practical synthesis of long (high kb range) DNA constructs.

Sardis Harward ‘08

Vitamin D serves a multitude of purposes within the human body, including those that relate to differentiation and control of cellular growth by means of apoptosis.  These experiments were designed to test the effects of the biologically active form of vitamin D, 1α,25-dihydroxycholecalciferol (1α,25(OH)2D3), on the growth rate of the osteosarcoma cell lines U-2 OS and SAOS-2.  The U2-OS cell line was allowed to reproduce until approximately 75% confluent, and the SAOS-2 cell line was allowed to reproduce until 40% confluent, both were then treated with 1α,25(OH)2D3 in concentrations ranging from 10-5 – 10-9M for 48 and 96 hour trials.  It was found that, rather than limiting cellular growth, exposure to 1α,25(OH)2D3 increased the rate of reproduction of the U-2 OS cells and had no significant effect on the SAOS-2 cells.

Andrew Ang ‘09

Gene therapy is a relatively new technology, which uses vectors to introduce novel DNA into cells. Gene therapy could potentially be used to correct genetic disease; however, there are many obstacles that must be overcome before this technique can be used clinically. One such issue is the targeting of gene therapy to specific cells in the body. The goal of the experiment was to create an epidermal growth factor (EGF)-liposome complex that could act as a targeted gene therapy vector to deliver death-inducing drugs or genes to cancer cells overexpressing EGF receptors on their surface. Streptavidin was used to attach biotinylated epidermal growth factor (EGF) to biotinylated arachidonic acid embedded in liposomes. In this experiment, the EGF-liposome complexes were used to transfect Saos-2 osteosarcoma cells with a GFP-mammalian expression plasmid. Transfection efficiency was measured using green fluorescent protein expressed by transfected cells.