Hi Mi, pour the concentrated TX-100 into a 50 ml conical tube to the 5 ml mark. Add PBS to the 50 ml mark and put the conical tube into an end-over-end mixer overnight.
After that you have a 10% TX-100 stock solution that is much easier to handle and dilute.
Traditionally it is weighed out on a scale. Drip the full-strength triton on a tared weigh boat. Use the diluent to get the triton out of the weigh boat.
For example, a 0.1% triton/PBS, weigh out 0.1 grams, dissolve in 100ml PBS.
Just take 10 ml of 1 X PBS in a conical tube. Take out 100 microliter and replace it by 100 microliter of triton x-100. This is your 10 ml of 1% triton x solution. Dilute 10 times to get 0.1% solution.