Series of dilution without a constant dilution factor?

I have to make a series of dilutions though the dilution factor is not constant.


I'm trying to understand how to carry out this dilution in the most efficient way as not to waste much solution.


**Series of dilution**


Initial dilution: 1/250


1/250 -> 1/500 -> 1/1000 -> 1/2000 -> 1/3000 -> 1/4000 -> 1/5000 -> 1/6000


I need to end up with 25µl in each tube. I've attached my solution in an image below though i'm not sure i'm doing this correctly as i would have to discard so solution.


My solution as depicted in the image:


[![enter image description here](https://i.stack.imgur.com/YATDq.png)](https://i.stack.imgur.com/YATDq.png)


