Laboratory Reports by Carolina Montañez-Miranda I. Microscopy and Photomicrography Microscopy is the technical field of using different types of microscopes, such as

electron, light and dissecting, to view samples and objects that cannot be seen clearly with the

naked eye. Once you identified under the microscope the organism you studied, you can take

pictures and edit them on the computer for better image quality. That’s why you can edit the

image while using bright field, dark field, Normaski (make the picture pop-out) or phase contrast

(makes a halo around the organism). The objective of this workshop was so we could learn how

to work well with microscopy and photomicrography techniques. To see if we fully understand

the workshop, we were supposed to find an organism and apply a specific technique to it. In my

case, I was supposed to find a c. elegans, use the phase contrast technique, and present it to

the class. In conclusion, it was a very successful workshop that provides techniques very useful

for future classes, assignments and research experiences such as working in Biology and

Botany Workshops.

II. Measurements – Micropipettes & Aseptic techniques

The correct use of pipetting is crucial for laboratory experiments. The micropipette has

two clicks, the first one is for suction and the second is for releasing the solution. Once we

mastered this process we are ready for any other experiment. In class, we were supposed to

create new colors by mixing the primary colors resulting in green, purple and orange. For the

aseptic techniques workshop, we were supposed to be able to isolate unknown bacteria using

different techniques. For the streak plate technique we took a sample and spread it on the

surface of the agar. This yielded individual colonies composed of a single type of organism. For

the smear technique, we needed to pass the bacteria from the surface of the agar to a slide.

When they were dried we did heat fixing so the bacteria died and adhered to the slide. Next we

stained the specimen and classified it as Gram positive or negative. The bacteria can be Gram

positive resulting in a purple color, this color indicates a high peptidoglycan content, but if the

bacteria allows this stain to be washed and accepts the counterstain ( pink color) they are called

Gram negative, indicating a low peptidoglycan content. At the laboratory we saw both, gram

positive and gram negative. Both of this workshops are crucial in chemistry and biology labs

and it is important we fully understand how to work with them. This can be applied to future

classes such ass Microbiology or future Research Summer Programs.

III. Workshop UNC - From DNA to Protein

During the workshop given to us by the students from University of North Carolina we did

four experiments: DNA extraction, Polymerase Chain Reaction, Running DNA on agarose gel,

and Running an SDS-Page gel. For the DNA extraction we isolated our own DNA using cells

from our mouth, and we used materials that can be found in any house such as Gatorade,

detergent, contact lens solution and alcohol. For the PCR, we were supposed to amplify the

DNA so we could identify if our patient had an oncogene. We made three different tubes: the

control with no DNA, the patient with test DNA, and the control with Oncogene. Once we

obtained the results from the PCR, we put them on agarose gel and performed electrophoresis.

Here, we can compare the results by observing the strands on the gel under UV light. Our

results were that our patient stained positive for the oncogene. In the SDS-Page experiment,

proteins are given a negative charge; this allows us to manipulate them to work with them in

electrophoresis. We were supposed to separate different sized proteins depending on their

mass in the gel. This gel was stained with coomassie solution and then removed with distaining

solution leaving only the results with color so we could compare the strands visually. This

workshop was a great experience. I did not only learn about laboratory techniques I had never

performed before, I also learned a little bit about graduate student lab work and their tips for us

undergraduates.

IV. Column Chromatography and SDS-Page

The objective of this workshop was to isolate protein, which are separated depending on

the shape, size and density. First we prepared an extract from egg white, that contained our

protein with the lysozyme, and then it was filtrated. Later, the student mentors demonstrated the

part when the lysozyme is being purified. It basically consisted of isolating the lysozyme from

the extract using ion exchange chromatography that is based on charge interactions.

Chromatography column packed with CM Sepharose can be easily manipulated so it can be

highly specific. To know if our protein has been purified or not, we did Electrophoresis (SDS

Page) in a gel previously prepared. With this we could check the purity of the final preparation.

The SDS treatment can eliminate the effect of differences in shape and charge. Once proteins

have been separated by electrophoresis, the gel is stained with coomassie solution and then

removed with distaining solution leaving only the purified proteins with color. These techniques

learned in the workshop can be used in Chemistry or Cellular Biology investigations; they can

also help scientists to prepare commercial products such as enzymes, nutritional proteins and

certain biopharmaceuticals.

V. Workshop MSU-Introduction to Neurobiology

The objective of this workshop was to introduce us to the area of Neuroscience and how

the brain and Nervous System acts on our bodies. During this workshop, presented by the

students from Michigan State University, we did five different experiments. These were based

on the Sensory System, the Motor System, and how external factors affect the Autonomic

Nervous System. The conclusions of these experiments were that the Neural System for taste

and smell are different but work together. We also found that sensory input is organized in the

brain like a map, and since the Motor System works in a matter of seconds reflexes are

involuntary and instantaneous. This knowledge gained in the workshop can be used in the

areas of Zoology, when the Nervous System is being studied, or also in Neurobiology.

Scientists, with this knowledge, can help treat Neurobiological diseases such as Alzheimer or

Parkinson’s disease.

VI. Protein – Protein Interactions

The objective of this workshop was to work with 3D structure proteins and try to discover

a new drug or medication to destroy a virus. Since we were separated in four groups, I was part

of group D, and we were responsible for the secondary screening. First, we re-ran the program

and checked the list with the top hits. From those we selected five based on affinity and FDA

approvement. Then we analyzed the interactions between the amino acids and the drug. After

that, we checked for a possible model refinement. In conclusion, we need to refine the drug

because the features that we found did not match the ones on the protein. The techniques

learned in this workshop can be used in Pharmacology or Toxicology. This can help improve

drugs and help scientists find more accurate medications.