1. Nicolle A. Rosa Mercado
BIOL 4997
Importance and Pipetting Practice
In this laboratory we reviewed pipetting concepts. We did large and small volume exercises with a
focus on micro-pipets. Concepts, such as the uses of the first and second stops, were discussed. It is
very important to keep these concepts fresh due to the fact that they are the most practiced
laboratory techniques. Pipetting is the key to any experiment because, if the amount measured is not
precise or if the pipet is contaminated with another substance, everything might go wrong. The
exercises were verified based on the color obtained at the end. The amount was verified by (setting
the micro-pipettes to the total amount of substances that were placed in the tube to ensure that the
amounts were measures accurately.
Microscopy and Photomicrography
During this laboratory, microscopy and micro-techniques were reviewed. It is of uttermost
importance for every scientist to know how to work with a microscope. Microscopes provide great
evidence of discoveries that have been made. They are also very helpful for studying different
microscopic organisms, such as bacteria. Here we reviewed the uses of different parts of the
microscope. We also learned how to take pictures using QCapture. The class was divided into four
groups and each learned a different micro-technique. Each individual was assigned to teach another
student how to use the technique he had learned. My task consisted of learning how to use a
fluorescence microscope to teach the technique to one of my colleagues. I was taught how to use the
phase-contrast microscope. In conclusion, each student learned how to work with two different
micro-techniques and reviewed the uses of the microscope’s parts.
Workshop UNC - From DNA to Protein
In this three day laboratory experience we were taught several genomics and proteomics techniques.
We reviewed techniques such as agarose gel electrophoresis and SDS-PAGE. The first day of the
workshop we were taught how to extract our own DNA using easy-to-find products. During the
second day, we ran a PCR and read the results through agarose gel electrophoresis. The
representatives of the University of North Carolina at Chapel Hill also helped us review the central
dogma of biology and how these procedures work. The third day we spoke about proteins and their
importance in lysosomal storage disorders. We discussed how to prepare SDS-PAGE, Western
Blots, and Coomassie stains. These techniques are very common laboratory tools. They are very
important in biology and, specifically, in genetics because they help scientists to differentiate genes
and proteins due to characteristics, such as their size, that can only be observed by using these tools.
A person who knows how to do these techniques has a great advantage in the scientific community.
Nanotechnology and Electron Microscopy
During this seminar offered by Dr. Wilfredo Otaño, we discussed concepts regarding nanoparticles
and electron microscopy. This experience helped us review the many applications that nanoparticles
have on biomedical research. One of the most important advantages provided by nanoparticles is
that they provide more surface area. Here we were taught procedures such as electrospinning. This
process is powered by an electrical charge that pulls a liquid added to a syringe and placed within

2. the device. This produces fibers that will contain whatever substance was added to the syringe. The
fibers are then submitted to a process called sputtering in which they are transformed into a metallic
state. After this process is completed, the fibers may be observed under an electron microscope. Dr.
Otaño also showed us around the physics laboratory and told us about the research that is being
developed within his lab. He explained the uses of all of the different machines within the
laboratory. Some of them were made by students that work in this laboratory.
Column Chromatography and SDS-Page
Through this seminar, Dr. V. Bansal reviewed protein concepts with the group. She emphasized the
importance of protein isolation and how this is made possible. Proteins can be isolated using
magnetic nanoparticles. These are used because they posses certain characteristics that make them
easier to work with in this field of research. For the isolation to be possible, certain steps are
required. These steps include precipitation techniques, filtration methods, centrifugation, and
chromatography. These concepts are important because their results may be used as catalysts,
therapeutics, or dietary supplements. After the proteins were isolated, following the procedures
listed in the handouts, each group had to prepare a SDS-PAGE. This last step was necessary in order
for us to know if we had isolated the correct protein. The SDS-PAGE gels were prepared during the
week in the RISE laboratory with the technician’s help. The results from my group were positive
due to the fact that it showed a band representing the first wash. This indicates that the protein was
appropriately isolated because the non-specifically bound proteins were removed.
Protein Interactions: an In silico approach
During the seminar Dr. Maldonado spoke about the different processes a prescription drug has to go
through before it may be prescribed. He taught us about structure based drug design,
pharmacophore models, and drug discovery strategies . In the hands-on part of this seminar we were
divided into four groups in order to complete four different tasks. The tasks were to identify optimal
targets for drug development (benzene mapping), to do pharmacophore identification and model
generation, primary screening, and secondary screening. My group was assigned the last step which
was secondary screening, or docking screening. In order to complete our task we used the NX
Client Application. Here we transfer a series of files from the computer to the application.
Afterwards we opened the file in CyberDuck, downloaded the file from NanoBio, and opened the
results in Excel. We sorted the compounds by affinity and selected the best five. Later we analyzed
the chosen substances using PyMol. Here we were able to take pictures of the compounds. The

3. topic of this seminar has a major importance in the biomedical field because it helps us predict how
effective a drug may be. It also helps us have a better understanding of how drugs work.
Phages & Proteomics
This seminar presented by Dr. Rubin consisted of two seminars. He spoke about
mycobacteriophages, which are viruses that infect bacteria that belong to the genus
Mycobacterium, and about proteomics. Proteomics is the study of protein functions and it is of
great help in this type of research. Dr. Rubin also discussed the importance of aseptic techniques
during research. During the practical part of the seminar, which lasted most of this semester, the
class was divided into pairs. We each had to bring a soil sample in which we had to look for phages
following the protocols provided by the professor. As soon as each group had at least one phage,
we had to do plaque screening and plaque purifications. Once my partner isolated some phages, she
prepared phage filtrates. After the proteomics conference that Dr. Rubin gave us, we analyzed
them. By using SDS-PAGE, we were able to determine the size of the two new phages. We also
had to prepare a progress report in which we had to present all the information regarding our
phages and the protocols that had been completed so far. This research is of great importance
because it provides a possible solution for diseases caused by antibiotic resistant bacteria.
Water sampling, testing, and statistical application
During this seminar, Dr. J. Arce spoke about the different factors affecting water quality and the
different techniques available to determine it. This workshop included an individual activity that
consisted of collecting a water sample from anywhere you could and testing it for total and fecal
coliforms. The sample should have been collected within a maximum of six hours before beginning
the protocol. After the sample was collected, ONPG and MUG enzymes were to be added. These
enzymes are able to identify total and fecal coliforms that may be present in the sample. The
sample had to be incubated for a period of twenty-four hours at thirty-five degrees Celsius. If the
sample presented a yellow color and had green spots when exposed to ultra violet radiation it
contained total and fecal coliforms and should not be considered drinkable. My sample did not
contain total or fecal coliforms. It was taken from a faucet in Cayey, Puerto Rico. The scientific
importance of this type of investigation is that it allows us to determine what water can be
consumed without being dangerous to our health. It also tells us if the water purification protocols
being used are providing effective results.