Question

Genetics/Bio3320 PS4 Due M April 6 AGACCGCGOOGCACGATTGCTCOOGGCIGTERCATOR C EATACTEOGATOGNANNTNGANGGTCNT CGCCCCGTCCTARCGADGCCCCACANAGTATANONGUCCACCCTACTONCCTNCCTTETCATCERONGEN GGGTGOCCACTTOGOCCAGAMOGTATATMMCCCCCCCNTCMNCTOCCTCANANGT NGENTONG CCCACCGGTTGAACCCCCTCCCATATAN GCONOCGTAGTTGACGCNGTETTCAICCAENGER 161 --- ATCAGACMACGTCAGGTGCGAGGAGTTGCACCCAAGTAGMAGECMAGACCACCTCTTCCNATCCNNCNCANACNA TAOTCTGTTGCAGTCCACCCTCCTGACCROCCTCATCTECCATEGGTTGGAGANGGTTAGGTTGGTGTTTGEE 241 +- Алтсласстататссалстусалалслалосселлесотест сресалалслассссссттесе TTTTAGTCGGTTATACAGCCTGAAGCTCTTGTTCTTGGGGTTGTTGCAGGANCCGCCTGTGTTCCOGTGGG GTGTIG CTAGTATGTATCCTCCTCAGAGCCTCCAGOTTOCGTCCCTCGTCGACNTTTCCTTTTTTTTCNTATTACATCCNTCCANG 321 +-- GATCATACATAGGAGGAGTCTCGGAGGTCGMAGGCAGGGAGCAGC GTAMAGGAAAAAAAAGTATANTOT NOOTAGGTEC b) You would like to sequence this fragment of DNA using Sanger/dideoxy sequencing. What would be the consequences of having 100% as much of each dideoxy nucleotide in the sequencing reaction as is normally put in, so that each dideoxy was present at half the concentration of the corresponding deoxyribonucleotide in the reaction mixture?

Answer 1

It is important to use half the concentration of deoxynucletides of dideoxy nucleotides to be used. Dideoxy nucleotides lacks oh group at 3' carbon of nucleotide and it is chain elongation blocker. If we use more dideoxy, it will block all the chain elongation reaction and we cannot sequence the fragment since there will not be different sized fragments and the reaction would have stopped at the earliest