Blood centers use a portable instrument that gives you exact measurement. Also a cheap and "dirty" way to do it is using a copper sulfate solution (google the formula). basically, if the drop of blood sinks it is greater tan 10mg/dl if not it is less. You can adjsut the solution for whatever concentration you want. So, go to your local blood bank and ask them to run a sample or make your own copper sulfate solution.  I believe this is something that one can get at a car parts store such as O'Reilley here in the US.

 Dear Sergio, thank you very much  your answer was helpful.

If you need to measure haemoglobin content in plasma or serum you can use the next spectrophotometric method:

TEST PROTOCOL

To determine the sample haemoglobin (Hb) level, the sample is measured, against water blank, on a ultraviolet/visible spectrophotometer at 576, 623 and 700 nanometer wavelengths.

The haemoglobin level is calculated using the following formula:

Hb = (A576 X 1.15) – (A623 X 1.02) – (A700 X 0.391) mg/mL

Regards

Thanks a lot Dear Carlos.

You are welcome. If you need further information i´ve been working with blood for the last years, although it was from mammals. 

Are you getting a good separation?

Dear Carlos thanks again

Yes, I got a good separation. Could you please, give me more information? what is mean these numbers (1.15, 1.02 and 0.391) I'm wondering for possibility measure the haemoglobin from the serum. actually, I'm new work with blood I don't have experience.

Regards, Sumeia

Dear Suemia,

Honestly, I never could find out what is the principle of the method. But is used in several laboratories for rapid estimations.

Thank you so much, I will follow this method.