Question

Google has offered a $1 million prize to the lab who creates the first sequence map of a dinosaur genome. We think we can do it, as we happened to get our hands on a preserved piece of dinosaur skin and were able to extract some DNA.

But our lab computer guy accidentally applied his randomization algorithm to our protocol. So now the steps are all out of order. Oops.

Can you put the following steps back in the correct order?, so we can get working on creating the sequence map?

      -       1.       2.       3.       4.      

Make a library of cloned fragments.

      -       1.       2.       3.       4.      

Cut many genome copies into random fragments.

      -       1.       2.       3.       4.      

Overlap sequence reads

      -       1.       2.       3.       4.      

Sequence each clone.

Answer 1

1. Cut many genome copies into random fragments - In shotgun sequencing, the DNA is cut into many random fragments.
2. Make a library of clones fragments - The fragments are inserted in to a bacterial cell and clones are created. These bacterial clones of different fragments are called Bacterial artificial chromosome library (BAC).
3. Sequence each clone - Each clone is sequenced using chain termination method.
4. Overlap sequence reads - Overlapping sequences, obtained from fragmentation and sequencing are assebled using a program.