Dna Fingerprinting Lab Report

Using Gel Electrophoresis and DNA Fingerprinting to analyze DNA samples

Laquandria M. Gibson

April 14, 2017

BSC2010L

Section #22

Sarah Ellmallah

Introduction

All cells contain a complex structure known as deoxyribonucleic acid (DNA). DNA is a chemical that determines how we are. The multiple combinations of its components are what makes a difference in each person. Long molecules of DNA are organized into chromosomes, which are grouped into 23 pairs. Then the chromosomes are broken down into short segments of DNA known as genes.

A gene is a basic physical and functional hereditary unit. Every gene contains a sequence of DNA that occupies a locus on a chromosome (Upadhyaya, 2017). Genes act as instructions to make proteins, varying in

Meaning for 50ml, 0.4 grams of agarose was weighed on a scale. And with a 250ml flask, 50ml of 1X TBE buffer was added as well as the 0.4 grams of agarose (Upadhyaya, 2017). Then plastic was placed over the flask and put in the microwave for one minute. After safely retrieving the hot flask from the microwave with a mitten, it was observed to ensure that the agarose was completely dissolved and was placed on a table to cool down to not burn the casting tray; once cooled 2.5µL of ethidium bromide was added to the agarose solution, which was used to illuminate the gel once placed under UV light (Upadhyaya, 2017). Before pouring the solution into the casting tray, a comb was placed on the middle of the edge of the tray to create wells once the gel was solid, allowing for multiple DNA samples to be used at the same time to be compared against each other. After the gel was solidified, the tray was repositioned as the positive pole was closer to the wells which then would not show much results. After adding 250ml of 1X TBE buffer to the tray, an almost equal amount on both sides, submerging the gel, the comb was removed and the wells were present (Upadhyaya,

As shown all are migrating downward going towards the positive side, as DNA is negative and the separation of bands are also shown clearly in Image 1.

The bands, all except lane 6, which was DNA from Suspect 1 cut with enzyme 1, were visibly shown as lane 6 did not have any bands that were visible to be compared against for crime scenes one or two.

Suspect’s one DNA is in lanes 4 and 5, with two different restriction enzymes in each. Lane 4, DNA with enzyme 1, did have bands that matched lane 2, crime scene 1 with enzyme 1. Lane 5, DNA with enzyme 2, did only had one marking that was the same as lane 2, the two others, did not match, as it was a different enzyme so when compared to lane 3, crime scene 2 with enzyme 2, the bands still did not align correctly, as lane 5 had an additional band than lane 3 did.

Suspect two’s DNA, in lanes 6 and 7 had two different restriction enzymes in each. Lane 6, DNA with enzyme 1, did not have any visible bands, as shown in Image 1. However, lane 7, DNA with enzyme 2, did match the bands present in lane 3, crime scene 2 with enzyme 2, but were a higher placement than lane 3’s bands were. Then, when compared to lane 2, crime scene 1 with enzyme, even though different enzymes, also did not have any bands that aligned