Question

Blood clotting can be prevented in a test tube by adding a little

Answer 1

Clotting of a blood is done by specialised cell in our blood which are known as platelets.

Answer 2

Sodium oxalate prevents blood clotting when added in a little proportion in a test tube. This characteristic feature is seen for blood clotting when added with sodium oxalate because there is a reaction initiated through sodium oxalate with the present action of the sample blood in the test tube. The clotting mechanism is immediately visible also.