Question

What was the size of your amplified DNA sampple? a.) 3.0 kb b.) 0.5 kb c.) 1.0 kb d.) 1.5 kb

Compare your fragments with the ladder to determine their size.

The DNA Ladder in Lane 1 has fragments of different sizes, in units of kilo-base pairs (kb):
Therefore, you should see eight bands in Lane 1. Their sizes are:

6 kb

5 kb

4 kb

3 kb

2 kb

1.5 kb

1.0 kb

0.5 kb

Material to Load	Lane
1 kb DNA ladder (NEB)	1
Sample DNA	2
Positive control	3
Negative control	4

PCR Setup Table
	Micro tube name
Material to add	Sample DNA	Positive control	Negative control
Deionized water	8 ?L (0.008 mL)	8 ?L (0.008 mL)	10 ?L (0.01 mL)
Sample DNA	2 ?L (0.002 mL)
Control DNA		2 ?L (0.002 mL)
Master PCR mix	40 ?L (0.04 mL)	40 ?L (0.04 mL)	40 ?L (0.04 mL)

Answer 1

You did not include a figure in your question. Then how could we determine the size of the amplified DNA sample. Please let me explain, how to determine it. First see the bands in the sample DNA (lane 2), select the band which would be the brightest band in the lane 2. Then compare this band with the ladder's band (lane 1), and you can identify the amplified DNA size. As for example, you see a bright band in lane 2, and then compare it with lane 1 which is a ladder. You observe that the band in sample DNA is matched with the band in ladder which indicates the 1.5 kb size. So, the amplified DNA size will be 1.5 kb. This is an example how to determine the size of DNA.

The negative control is used here to see if there is any contamination occurred in the deionized water.