load=1PP8

define set1{dna and *.O?'}
define set2{dna and *.OP?}
define set3{dna and nitrogen}

restrict dna
select all
cpk 0
pause

select set1
cpk 50
pause

select set1
cpk 0
select set2
cpk 50
pause

select set2
cpk 0
select set3
cpk 50
pause