Iteration in array of three columns and ten rows

Hi all, i have one question. I want to iterate in array follow the next steps:

i) First i analize one column and one row. The name of array with data is DNA and the name of outcome is "serial".

if true
  % code
t=3 ;number of columns in array DNA
n= length(DNA)

for i=1:n

    if DNA(i,1)==1 % if first column and "i" row is one, then the outcome row array is one
       serial(i)=1;

    elseif DNA(i,1)==-1 % if first column and "i" row is -1, then the outcome row array is -1 
           serial(i)=-1;

    elseif DNA(i,1)==0 % Here i start to having doubts. If i have zero, i want analize the same row in  %    %column two

            for j=2:t;

                if DNA(i,j)==1 % i analize the same row and column two
                   serial(i)=1;

                elseif DNA(i,j)==-1
                   serial(i)=-1;

                elseif DNA(i,j)==0 % if i have zero in same row in column two, i want to analize the same %row in column three and look like my code is wrong...

end

I put the example with "i" arrows and three columns but my data is generic:

i=1,2,3,4.......n % rows j=1,2,3,4.......t % columns

How can i code this?

Thank you very much