PCR and Gel Electrophoresis Questions -1 PDF

Preview

Summary

Lab assignment homework...

Description

Name Bio 159 PCR and Gel Electrophoresis Question set (10pts) Read the PCR paper. Then, answer the following questions in your own words. Type your answers and print on a sheet of paper to turn in. 1. List two advantages PCR gives in either a research or a clinical laboratory. -

Can detect pathogens Used on forensic medicine to identify criminals

2. What is the role of primers in PCR? -

The primers are used to specify the exact DNA product to be amplified since they are short DNA fragments with a defined complementary sequence.

3. Describe the steps of denaturation, annealing, and extension during PCR. -

Denaturing: the solution is heated above its melting point so that the strands of DNA separate Annealing: the temperature is then lowered to allow for the primers to bind to the DNA sequence Extension: The temperature is raised again and the DNA polymerase extends the primers by adding nucleotides and developing a new DNA strand

4. A limitation of PCR is that the primers can bind to other sequences that are not the target sequence. This means millions of copies of the non-target DNA will be made. If you examined your results using gel electrophoresis what might you expect to see? - You might see a bunch of copies of DNA that are not what you are looking for

5. The gel below shows the known DNA ladder in the first and last lanes. Using what you know about gel electrophoresis, answer the following questions:

A. Which lane has the longest DNA fragment? - 1 and 10 B. Which lane has the shortest DNA fragment? - 8 C. The ladder in the first and last lanes is a 1 kilobase (kB) DNA ladder. The three brightest bands in the ladder correspond to 5,000 base pairs (bp), 500 bp, and 1,500 bp. Using what you know about how gel electrophoresis works, label all three bands with their bp sizes. - 996 – bp band, 810-bp band, and 621-bp band respecively...