About Insert, Insert size and MIRA mates.file

[aarthi.talla]

Hello All,
I am confused about what an Insert actually is ? And what is an insert size ?
I am dealing with 454 paired end data. How is a Linker different from an Adaptor?

I will be using MIRA's sff extract to extract the fasta and qual files from the sff files.
So does the sff files have read info this way:

|-----75----|------------------------100-----------------|-----75-----|

i.e - Seq.forward - Linker - Seq.reverse ??

In the above, what is an insert ? and whats the size ?
So do each of the reads in an sff have the above format ?

So in the MIRA's mates.file setup can I just use the following default format for the mate pairs ?

pair (.*)\.f (.*)\.r

Please help me out with my confusions:

Thanks

Aarthi

[aarthi.talla]

In addition, in the Newbler metrics of the assembly, for a particular sff file it says about the 'pairedReadStatus'
pairDistanceAvg = 2247.3
pairDistanceDev = 561.8

Now is this information about the assembly status or the raw reads status ?
Is pairDistanceAvg the Insert size ????