You can predict that when you centrifuge whole blood with anticoagulant (e.g. sodium citrate) at about 500-3000 x g for 15 min at 20-24°C, you will get about 40-45% (= 40-45% hematocrit) as red blood cells (bottom layer), and therefore 60-55% (upper layer) as plasma. There will be a small intermediate phase that is called buffy coat that contains platelets and white blood cells. As the g force or the time of centrifugation increases, there will be less platelets and WBC in the plasma phase. The hematocrit is usually 40-45% (not 7%), so from 600 ml of whole blood you can expect to get 600 x 55-60% = 330-360 ml of plasma.

I dont think that there is one formuls that could precisely vsculate the amount of plasma. First of all it depends on the hb. Moreover, it also depends on the type of tube. Furthermore, eventhough you have taken all these factors in to account it is important to realize that the tube might not be ffully filled. Finally, it is dependent on g's which in turn is dependent on the type of rotor. Ofcourse is you only want platelet free plasma it is prevert to go higher in g's yhan wanting to have platelet rich plasma.

There is no unique formula for this purpose. The amount of maximum plasma volume to be collected is related to the volume and Hct of the original blood unit, the Hct of the resultant packed red cells, whether or not the collection of plasma has therapeutic purposes (i.e. it is plasmapheresis), and other factors.

Dear German

I recommended your wise questions because it seems to have attracted a lot of research interest, understandably as it is an important practical questions of importance to many of us in research. Kind regards, Thierry

The formula provided by Thierry (VxHTC) is the only one that can be used to calculate the volume of plasma that can be obtained by centrifugation. However, the obtained result is only the one theoretically attainable since the real result (=volume of plasma) is alway lower. The difference between the real and theoretical volumes depend on the centrifugation speed and timing as well as on the impossibility to recover completely after the centrifugation the plasma obtained. To these variables you have to add the so-called trapped plasma which remains between the RBCs on the bottom of the tube despite any "high" centrifugation. In the daily practice the trapped plasma is the responsible of the differences between the manual (higher) and the automated HTC (lower) since this last that is calculated as MCVxRBCs do no contains any amount of plasma

The separation of plasma from blood cells is therefore critical for the accuracy of diagnostic tests because cellular fractions can create discrepancies in analysis. The conventional method for separating the cellular fraction from whole blood is by centrifugation, which requires a laboratory infrastructure. In the last decade, intensive research to scale down experimental processes has seen unprecedented advances in microfabrication and related techniques that have led to utilization of the micro-level phenomenon to accomplish a myriad of physicochemical separation processes. (Article Plasma Separation from Blood: The 'Lab-on-a-Chip' Approach

From Hematology.org " The blood that runs through the veins, arteries, and capillaries is known as whole blood, a mixture of about 55 percent plasma and 45 percent blood cells. About 7 to 8 percent of your total body weight is blood. An average-sized man has about 12 pints of blood in his body, and an average-sized woman has about nine pints. "

The final volume of plasma is: 600(mL) x (0.93) = 558

Consider that it, is very difficult to recover 100% of plasma. So 558mL is the theoretical final volume

I don't think there is a particular formula to calculate the amount of plasma that can be extracted from the whole blood, rather the amount of plasma that could be removed depends on the HCT or HB concentration of the blood, time and RPM of centrifugation

I've transfer-pipetted thousands of spun-down EDTA blood tubes to collect plasma and if we're being careful and avoiding the Buffy Coat as well, we're lucky to get 35% of the original volume.