blood,plasma and serum.

[chen.lie]

hello everyone
I tend to confuse blood,plasma and serum.
If i'm not mistaking,plama contains cells and cell fragments.
Serum is derived from plasma and contains the same things except blood clotting proteins.
But what is blood in all of that??? Rhooo i'm soo confused :S

I hope that you'll be able to help me.

Regards

[sdekivit]

blood: cells + platelets + proteins
plasma: centrifuged blood -->cells are out (only fluid and proteins and so on)
serum: the fluid that stands above coagulated blood. Contains growth factors.

[MrMistery]

In our high-school books they teach us that serum is plasma without proteins

[sdekivit]

it's not. serum is the fluid that is found on top of coagulated blood. Due the trapping of platelets they begin to degranulate and that's why in serum there are also growth factors.

--> that's why serum is used cell cultures

[Morris]

Serum contains humoral immunity; it'used in cell cultures for it and for growth factor too.

[chen.lie]

thank you

[Dr.Stein]

- Blood is a special supporting connective tissue that consisted of corpuscles compartments i.e. RBC, WBC, & platelets and liquid compartments or plasma.

- Plasma is a liquid that contains proteins, nutrients, hormones, etc. dissolved materials and also clotting factors.

- Serum is like a plasma but just without clotting factors.

Both plasma and serum locate in the top of the surface of centrifuged blood due to their molecule weight compared to corpuscles part.

How to obtain plasma and serum?
- To get plasma, you must add anticoagulant, e.g. heparin to prevent platelets release thromboplastin (one of clotting factors) that triggers the cascade reaction of blood clotting, means that after centrifugation the clotting factors are still there. Another example of anticoagulant is EDTA, it inhibits the enzymatic catalysation of a particular step in the clotting cascade that needs Ca-ions (thanks to sdekivit )

- To get serum, you do not need to add anticoagulant. You will directly centrifuge your sample blood.

If you want to use or analyze corpuscles, it will be much better to add anticoagulant to your blood sample before centriguge it because it will keep corpuscles in better condition, not clot one to another.

If you want to analyze the liquid fraction, out of clotting factors, you can add anticoagulant or not to your blood sample.

[sdekivit]

EDTA doesn't prevent the release of thromobplastine by platelets --> it inhibits the enzymatic catalysation of a particular step in the clottingcascade that needs Ca-ions --> EDTA catches the Ca away.

[Dr.Stein]

Sorry, I just meant to mention the anticoagulation agents in the first idea, not their specific function. Thanks for correction, I will edit my post