S-STEM Scholar Jessica Sabel's Blog

Introduction:   This week, major focus was placed on developing an outline for procedures and the purity of the  D. aquaticus  samples. There are many opportunities for error while working in the lab. Contamination and improper planning were some difficulties we experienced in the lab this week. Developing a thorough plan will minimize the risk of error because every aspect of the experiment has already been planned out. This also leaves less opportunity for contamination, because we have more confidence going into the procedure. Contamination has affected our project before while working with kanamycin, due to improper pipetting or contaminated TGY. Although we have reformed our technique since then, contamination has become an issue again. Though the use of gram stains, we will hope to identify the organisms that contaminated the bacterial sample, and therefore determine the cause of contamination.  This will lead to improvements in preparation and technique g...

  Introduction: The Minimum inhibitory concentration of kanamycin was achieved with our previous work, with a concentration of 1.75 ug/ml. The only issue is that there is no kanamycin resistance gene on the plasmid that we will be working with in transformation. Instead of moving forward with kanamycin, we are starting again with tetracycline, as the plasmid we are working with has a tetracycline resistance gene.   Tetracycline is a protein synthesis inhibitor that belongs to its own class of antibiotics. It binds to the 30S subunit on the ribosome, preventing protein synthesis from occurring. This antibiotic has been used in our MIC testing before, but the concentrations of tetracycline added were too high to see any growth. The smallest concentration used was 0.0975 ug/ml, and this only gave us an absorbance reading on the spectrophotometer of 0.02. Because of this, we will be testing even smaller concentrations of tetracycline, working with ng/ml. This will be performed wit...