#returns the ratio of DNA:Water for DNA dilutions for a given amount of DNA.
def dilution_maker(conc, DNA_amount=50):
  dil_factor=1
  if conc>DNA_amount:
    dil_factor=conc//DNA_amount
    if conc%DNA_amount>0:
      dil_factor+=1
  dil_conc=conc/dil_factor
  #print(dil_conc) #prints the final diluted concentration
  return(str(conc)+ " " + "(1:" + str(dil_factor-1)+")") # return conc, dil_factor, dil_conc in the format '[conc] ([DNA:Water])'

# example using a sample with a concentration of 233ng/ul and required amount of 50ng for the assay.
dilution_maker(233,50)