how do I make....?

Question

antibody dilutions of:

1:25
1:50
1:100
1:200
1:500

thanks!

sorry I should have mentioned I'm making 100ul of each

Answer 1

Theodor you are answering as if antibodies are abundant chemicals.
Usually you have extremely small amounts of antibody and solution.

First of all what do you want to use it for?
Do you want for example 1:500 to be the concentration of a stock solution or your working concentration?

If you want to make a dilute stock solution from a more concetrated one then you take 1 microliter of your concentrated antibody solution and mix it with 24 microliters of proper solvent.

For dilution always use C1V1=C2V2 =>
V1=(C2/C1)*V2

So if you want a final of 25 microliters of 1:25 you need
V1=(1/25) * 25=1 microliter of initial solution and V2-V1=25-1=24 microliter of solvent.

If you want 100 microliters of 1:25 you need

V1=(1/25)*100= 4 microliters of initial solution and V2-V1=100-4=96 microliters solvent

and so on

This way you can calculate for all.

You can also use the first solutions for making the others (e.g. you dilute 1:10 part of the 1:50 to get the 1:500)

Normally you should follow Theodor's advice but when you are at this order of magnitude of volumes it is not possible and you have to do this approximation.

Answer 2

You would dilute 1 volume of antibody in 24 volumes of liquid. Then 1 volume of bacteria in 49 volumes of liquid. ETC ETC

Answer 3

take your pure antibody and 5 100ml 1 200ml and 1 500ml volumetric flasks.
4 ml in the first 100ml flask. Fill to line with solvent.
2 ml in the second 100ml flask. Fill to line with solvent.
1 in the third 100ml flask. fill to line with solvent.
1 in the 200ml flask. Fill to line with solvent.
1 ml in the 500 ml flask. Fill to line with solvent.

This will give you volumetric ratios. If you don't have that much antibody and you have better measuring devices you can just use smaller amounts in smaller flasks.