What is the difference between a blood clot and a plasma clot?

Question

(Within the scope of Immunology)

Answer 1

I'm sure you know this already, but let me just quickly review the composition of blood and plasma:

Blood is actually a mechanical mixture (not a solution) of blood cells and plasma.  This is why when you centrifuge whole blood (or simply let it sit long enough, somehow without clotting), you'll get blood cells settling at the bottom of the tube, and a yellow liquid floating at the top.

This yellow liquid is plasma, and it contains all the dissolved components of blood, including all the ions (such as sodium, potassium, chloride, etc), proteins, but also clotting factors, which are enzymes and proteins capable of polymerization.

When the "coagulation cascade" is activated (which is possible even in the absence of blood cells), the various clotting factors initiate, amplify, and propagate the polymerization reaction of fibrin, and in the end you end up with a clot.  This is a plasma clot.  It can exist without any blood cells.

In real life, blood cells are suspended in plasma at all time, so when the coagulation cascade is activated, blood cells (especially red cells, since they are present in the largest numbers) get trapped in the clot, giving it a red colour.  This is a blood clot, which we commonly known as a "scab".  

Of course, while red cells give a blood clot its characteristic red colour, it is the platelets which play the biggest role in the formation of a blood clot.  Platelets facilitate various steps of the coagulation cascade:

http://ccforum.com/content/9/s5/s15/figu...

In short, a blood clot forms a lot faster (because of platelets) and has a different colour (because of red blood cells).

I hope I answered the question I think you are asking.  (If not, clarify what exactly you want to know, and one of us will try again....)

Answer 2

A blood clot (in a collection tube) contains very little if any fibrinogen.  The clotting factors have converted the fibrinogen to fibrin and created the clot.  The liquid portion once the specimen has been spun down is serum.  

Plasma contains fibrinogen.  The anticoagulates in the collection tubes prevent the clotting factors from converting the fibrinogen to fibrin.  Plasma doesn't clot.

For the vast majority of tests (in  immunology) these days either serum or plasma is acceptable as a specimen.

within the scope of immunology.. serum specimens that haven't adequitely clotted can and do cause interpretation problems with some of the test kits.  therefore if a plasma specimen is acceptable, it is the better choice.  it won't leave fibrin threads that can make the test difficult to read.

Answer 3

Blood contain Red Blood Cell

plasma Doesnt contain RBC