A Dried blood test is a test you can order to your house and take at home. It will show you what Omega 6 to Omega 3 ratio you got in your cells. 

What's important to know is that to measure the Omega 3 balance, you need to do it with a dried blood test instead of a fresh blood test. This is because when you go to the doctor and do a regular blood test, they will separate the plasma from the rest. Most often, it's the plasma that they are using in their measurements. And this is not giving you an accurate read because these cells only live for about 7 days. So if you have eaten fish once or twice within 7 days, these numbers can look good... 

When you measure the red blood cells, they are living about 120 days. This gives you a better understanding of your overall balance in your cells, even how your liver cells or brain cells are doing.