Why tranform using DH5 alpha -> SM10 λpir?? - (Oct/31/2012 )

Hi I just constructed a plasmid and I am told that I will be transforming into DH5 alpha then into SM10 λpir.

My question is why do I tranform using DH5 alpha first instead of using SM10 λpir directly?

Please provide as much detail as possible, I'd really appreciate it.

Thank You very much

May be cloning and copy number will be more in Dh5 alpha strain.
But it does not matter if you transform directly into SM 10 lambda pir

E. coli SM10 λpir strain contains the pir gene (lysogenized with λpir phage) and it is designed for cloning and propagation of plasmids with R6K origin of replication sequence (such as pUT mini-Tn5 vectors). The plasmids containing the R6K origin of replication require the R6K-spicific replication protein lpir gene for propagation.
Characteristics
The genotype of the strain is KmR, thi-1, thr, leu, tonA, lacY, supE, recA::RP4-2-Tc::Mu, pir

from: http://www.biomedal.com/bls/en/strains.html

What kind of plasmid do you have? More specifically: origin of replication? other characteristics?

Sorry for the delayed response:

I am using the vector pdsRed-express2; I am not sure about the origin of replication though...