I'm trying to create a random sequence of 100 DNA bases, with an equal number of A,C,G and T, but I can't make it happen.

I'm trying to create a random sequence of 100 DNA bases, with an equal number of A,C,G and T, but I can't make it happen. My code is:

total_bp=10000;

%open file
fid=fopen('Seq_Out.txt','w');

for i=1:total_bp
%random DNA sequence
SeqLength=100;
Seq=randseq(SeqLength,'Weights',[0.25 0.25 0.25 0.25]);

%write to file
fprintf(fid,'%s\n',Seq);
end

fclose('all');

Answer 1

[Walter Roberson]

Before the loop:

SeqLength=100;
bases = repmat('ACGT', 1, SeqLength/4);

The replace your

SeqLength=100;
Seq=randseq(SeqLength,'Weights',[0.25 0.25 0.25 0.25]);

with

Seq = bases(randperm(SeqLength));

[Nitzan Kahn]

It works perfectly, thank you!

[Radhwan Jawad]

How can I read a DNA sequence from NCBI and store it in array or in a specific variable

[Image Analyst]

@Radhwan Jawad start a new question for this.

@Nitzan Kahn If this solves the question for you then please click the "Accept this answer" link to award @Walter Roberson "reputation points" for the answer. Thanks in advance. 🙂