hey dear, don't be like that.. mayb seng888 got some missunderstanding about sperm bank... so he act like that 
to Seng888, sincerly hope ypu search around google for a defination of "Sperm Bank". This is a total CLEAN bank and not what you think it's dirty..
do think about a couple that cannot get even ONE child after 10 years of their merriage.. and if this is cost by the man's sperm is not healthy (u always can have sperm count test in any medical lab) or high in motility? what will you do if you both really want a child? ofcourse you cannot say "I go find another girl/ women" or the wife say "i go find another man".. must know, they LOVE each other..
so, the solution is:
1) if due to sperm problem: go to sperm bank to find a healthy sperm. the Doctor there will have the advance technology to test everything that you want. even you can choose a good DNA profile one.
2) if the women cannot produce eggs, then they might need to look for a DONOR, and mayb they also need a "carry mother"...
this services is all now available in few famost privite hospital in malaysia.
so what do you think it's so dirty???
hey, it's all done in clean room, sterilised environment with all those really professional doctor.
this is the achievement of Science, and all human should proud of it
because we all don't know how normal and how long we can keep strong..
hey, you can always choose to STORE your sperm in sperm bank. this can stored up to >20 years, if i not misstaken. so if really one day in the future, you don't have anymore healthy enough sperm, then you can go back to this "bank" to draw your "Money"
mean your original sperm 
hope you understand this is Science, don't miss up Science with "dirty job"
check everything before comment.
take a deep breath when facing anything that make you "angry", then think twise..