Preparing standard dilutions for a standard curve question?

Actually, serial dilutions are generally made as follows: You have a stock solution of known concentration. You then dilute that say, 1:1, giving you a solution that is now 1/2 the original concentration. You then take THAT new solution, and dilute it, say, 1:1 giving rise to yet another new solution that is now 1/4 the original. You keep doing this over and over. That is really what a serial dilution is. The other way is to take the original and use it to make all the suceeding solutions. So, you might dilute the original stock 1:1, and then dilute the original stock 1:4, and then dilute the orignal stock 1:8, and so on. I can tell you from persoanl experience that the disadvantage to the second method is that if you make a mistake in making the original stock, then ALL solutions are wrong. If you make a mistake in serial diltutions, you can generally track it down, and make a correction. On the other hand, if you make the original stock correctly, then the precision in using the stock to make all subsequent dilutions is better than in serial dilutions.