You can use any online calculator. I'm providing here a link for such a calculator.

https://www.bioline.com/media/calculator/01_04.html

Mass in grams per liter divided by the molecular weight equals the molarity.

You have 0.6 mg/mL this equals 0.6 grams/Liter

0.6 grams/liter divided by 18,000= 0.000033 molar = 33 micro molar.

Same like you'd calculate the molarity of a 20mg/mL NaCl solution.

Mr = 18.000g/Mol.

That depends, what is the molecular weight of your protein?

Hello Astelia Francois

Philip G Penketh is correct.

The Dalton symbol Da, is also sometimes used as a unit of molar mass, with the definition 1 Da = 1 g/mol.

Therefore,

1Da= 1g/mol

1 kDa = 1000 g/mol

So, 18kDa = 18000g/mol

Now

18000 g ---- 1M ---- 1L

18g----------1M -----1ml

18000mg --- 1M ---- 1ml

The protein concentration is 0.6mg/ml.

Therefore,

0.6mg x 1M / 18000mg = 0.0000333M = 0.0333mM= 33.3μM.

So the protein concentration (in μM) as per the size (18kDa) and concentration (0.6mg/ml) is 33.3μM.

Best.

x mg/ml is same as x g/L. Now, if you know the molecular weight of your protein (Y), then (x g/L)/ Y g/moles will give you concentration in molarity.

Protein=0.6 mg/ml= 600mg/L=600/18000 millimole/L=1/30millimole/L=1000/30 micromole/L=33.33micromole/L

Divide the concentration (mg/ml) by the molecular weight.