Genetics and Genomics Lab Report 4

4/20/12

BIOMG 2810

Lab Report: Experiment 4

Gel #1, Friday, room 41

1.

i. Order of PCR products in lanes (left to right)

lane 1: CSH61 with primer pair 2

lane 2: CSH55 with primer pair 2

lane 3: exconjugant with primer pair 2

lane 4: CSH61 with primer pair 7

lane 5: CSH55 with primer pair 7

lane 6: exconjugant with primer pair 7

ii. Results of electrophoresis

Amplification from CSH61 using primer pair 2 produced no PCR product.

Amplification from CSH55 using primer pair 2 produced no PCR product.

Amplification from the exconjugate using primer pair 2 produced a PCR product about 560 bp.

Amplification from CSH61 using primer pair 7 produced no PCR product.

Amplification from CSH55 using primer pair 7 produced a PCR product of about 680 bp.

Amplification from the exconjugate using primer pair 7 produced no PCR product.

2.

Primer pair 2: 560 bp

Primer pair 7: 114772 bp; there is no PCR product because the fragment is greater than 4 kb

3.

a. PCR of CSH61 and CSH55 served as controls. CSH61 allowed us to see the results of PCR with each primer pair on a genome containing lacpro, while CSH55 allowed us to see the effects of PCR with each primer pair on a genome lacking lacpro. Because of these controls, we are able to determine whether the exconjugant contains lacpro.

The DNA ladder serves as a control for the electrophoresis because the ladder contains DNA strands of known molecular weight, and these fall in a characteristic pattern on the gel. If this pattern is visible, the electrophoresis can be assumed to have worked, but if the observed pattern differs from the expected, we know that the gel is unreliable.

b. The earlier primer in primers in primer pairs 2 and 7 are identical. These each locate to a site upstream of the deletion. The later primer in primer pair 2 locates to a site that is within the deletion. This is shown by the absence of bands in the gel below CSH55 with primer pair 2,...