There are different species of BN. This almost by definition means that certain BN will NOT cross breed. Peppermints are a different species from Albino (sp3). I very much doubt that they would cross breed and if they did I would also ask why? If you are asking because you don't want them to breed I would say don't worry.
Mystix212 you are right in that different "Strains" would breed because they are the same species. Albinos (sp3) breed with brown (sp3) breed with longfin (sp3) because they are the same species.
Dylan