1. Sequencing DNA – the Sanger Method – the most-popular way (one of many methods)
A primer binds to one of the DNA strands at a specific location (such as the Cyto B gene)
Nucleotides (dNTPs) are floating around in solution
A DNA polymerase begins to synthesize a new stand of DNA
Then a “fluorescently-tagged” ddNTP
(di-deoxynucleotide triphosphate) gets incorporated into the growing chain of DNA
but terminates the chain (it cannot be elongated).
Scientists use 4 different color “glowing” ddNTPs:
One color for each of the 4 bases of DNA
(eg. green-glowing “A”, blue glowing “C”, etc.).
The DNA fragments – all copied to different lengths –
are analyzed by “capillary” gel electrophoresis.
Smaller fragments run faster. Fragments arrange by size!
A detector “reads” the color of light as each DNA fragment flows past.

3. Cytochrome B sequencing (1 person)

4. Text format of DNA sequencing
Comparison of Cyt B between samples 01 and 02: (1 difference in 303 bases)
Query CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
Query CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Sbjct CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Query TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Sbjct TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Query GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGGCGAGGCCTATAT 240
Sbjct GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGGCGAGGCCTATAT 240
Query TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACCATA 303
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| |||
Sbjct TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
Text format of DNA sequencing
A comparison between 3 individual’s
Cytochrome B gene (303 bases)
1 base difference
between persons 1 and 2
Comparison of Cyt B between samples 01 and 03: (2 differences in 303 bases)
Query CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
Query CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Sbjct CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Query TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Sbjct TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Query GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGGCGAGGCCTATAT 240
||||||||||||||||||||||||||||||||||||||||||||||| ||||||||||||
Sbjct GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGACGAGGCCTATAT 240
Query TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACCATA 303
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| |||
Sbjct TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
2 base differences
between persons 1 and 3
Comparison of Cyt B between samples 02 and 03: (1 difference in 303 bases)
Query CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
Query CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Sbjct CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Query TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Sbjct TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Query GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGGCGAGGCCTATAT 240
||||||||||||||||||||||||||||||||||||||||||||||| ||||||||||||
Sbjct GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGACGAGGCCTATAT 240
Query TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
1 base difference
between persons 2 and 3

5. A comparison between 3 humans and Neanderthal
Comparison of Cyt B between sample 01 and Neanderthal: (3 differences out of 303 bases)
Query CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
|||||||||||||| |||||||||||||||||||||||||||||||||||||||||||||
Sbjct CCATCCAACATCTCCGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
Query CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Query TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Sbjct TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Query GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGGCGAGGCCTATAT 240
||||||||||||||||||||||||||||||||||||||||||||||| ||||||||||||
Sbjct GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGACGAGGCCTATAT 240
Query TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACCATA 303
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| |||
Sbjct TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
A comparison between 3 humans
and Neanderthal
in the Cytochrome B gene (303 bases)
3 base differences
between person 1 and Neanderthal
Comparison of Cyt B between sample 02 and Neanderthal: (2 differences out of 303 bases)
Query CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
|||||||||||||| |||||||||||||||||||||||||||||||||||||||||||||
Sbjct CCATCCAACATCTCCGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
Query CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Query TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Sbjct TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Query GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGGCGAGGCCTATAT 240
||||||||||||||||||||||||||||||||||||||||||||||| ||||||||||||
Sbjct GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGACGAGGCCTATAT 240
Query TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
2 base differences
between person 2 and Neanderthal
Comparison of Cyt B between sample 03 and Neanderthal: (1 difference out of 303 bases)
Query CCATCCAACATCTCAGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
|||||||||||||| |||||||||||||||||||||||||||||||||||||||||||||
Sbjct CCATCCAACATCTCCGCATGATGAAACTTCGGCTCACTCCTTGGCGCCTGCCTGATCCTC 60
Query CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct CAAATCACCACAGGACTATTCCTAGCCATGCACTACTCACCAGACGCCTCAACCGCCTTT 120
Query TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Sbjct TCATCAATCGCCCACATCACTCGAGACGTAAATTATGGCTGAATCATCCGCTACCTTCAC 180
Query GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGACGAGGCCTATAT 240
Sbjct GCCAATGGCGCCTCAATATTCTTTATCTGCCTCTTCCTACACATCGGACGAGGCCTATAT 240
Query TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sbjct TACGGATCATTTCTCTACTCAGAAACCTGAAACATCGGCATTATCCTCCTGCTTGCAACTATA 303
1 base difference
between person 3 and Neanderthal

6. Video about sequencing and the Human Genome Project:
PBS.org>Gene Reader
Secrets of the sequence - Missing Gene in Breast Cancer video
Timothy Ray Brown – Berlin Patient – Video