what is the different between blood plasma and serum?

Answer 1

It is simple.
If you remove all the corpuscles from the blood, you are ;left with blood plasma.
If you remove dissolved fibrinogen protein from the blood plasma, you are left with serum. The protein fibrinogen is converted into fibrin which precipitates out and then it can be removed from the blood plasma to get serum.

Answer 2

Well, this is the difference: plasma is the liquid component of blood where all the blood cells swim. Serum is that liquid separated from the cells, for example, when you take a blod sample and leave it in the test tube. It clots and the Serum separates from the cells and you can see this yellowish fluid. Plasma is when the liquid is mixed mith the cells, not separated

Answer 3

serum is the clear liquid part of blood AFTER coagulation, devoid of clotting factors as fibrinogen that has separated from the red blood cells after being drawn into a vial without having any anti-coagulant factors added to it.

plasma is the liquid, cell-free ( part of blood, that has been treated with anti-coagulants) that has separated after centrifugation. (spun in a centrifuge to separate the cells)

Answer 4

Blood samples obtained in drunk driving cases are generally — but not always — analyzed as whole blood (sometimes called "legal blood"). If the sample is withdrawn for medical purposes, however, the test will probably be done with serum (often referred to as "medical blood"). Serum is the clear yellowish fluid obtained from separating whole blood into its solid and liquid components (usually by centrifuging the sample); the liquid portion of the blood is called plasma, which is similar to serum. A third method involves precipitating proteins from the blood sample and centrifuging it; the result is a clear liquid called "supernatant," which is then analyzed.

Will analysis of serum/plasma or supernatant result in the same blood-alcohol readings as analysis of the whole blood? In a study entitled Distribution of Ethanol: Plasma to Whole Blood Ratios, Hodgson and Shajani, 18 Forensic Science journal 73 (1985), scientists attempted to determine the answer to this very question. The conclusion: Blood-alcohol concentrations in plasma were approximately 11 percent higher than that of whole blood, and those in supernatant samples were about 5 percent higher.

Thus, for example, evidence of a subject's blood-alcohol analysis indicating a .10 percent BAC may in fact reflect a true .09 percent if the plasma separation method of analysis was used. This has been confirmed in another study in which researchers concluded that a "person with an ethanol concentration of [.09 percent] in whole blood could have a reported concentration above [.10 percent] if either serum or plasma is analyzed." Winek & Carfagna, 11 Journal of Analytical Toxicology 267 (1987). Since many states permit the three types of "blood samples" to be used interchangeably in blood-alcohol analysis, counsel should certainly determine which type was actually used.

A simple technique for visually demonstrating the concept of testing blood that has aged and been subject to possible fermentation is to bring in a fresh vial of blood and compare it to the evidentiary sample withdrawn months earlier from the defendant. The fresh blood will be bright red, while the test sample will be nearly black.

For a study that found that serum-alcohol concentration can be up to 20 percent higher than blood-alcohol concentration, see Frajola, Blood Alcohol Testing in the Clinical Laboratories: Problems and Suggested Remedies, 39(3) Clinical Chemistry 377 (1993).

For legal case decisions, see Commonwealth v. Wanner, 605 A.2d 805 (Pa. Super. 1992), where the defendant appealed his DUI conviction on the grounds that the evidence of his blood-alcohol concentration was based on tests conducted on blood plasma rather than on whole blood, as required by statute. The appellate court agreed, citing the Bartolacci opinion; although that case addressed the use of blood serum rather than plasma, both involved tests on only portions of the blood. The court further found that tests on plasma resulted in BACs 15 to 20 percent higher than tests on whole blood.




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Will the argument over the use of colloids vs crystalloids in critically ill patients finally come to an end? Before answering this question, it is important to consider how the issue evolved. Colloids provide the same hemodynamic effects with less volume infused and cause less edema. And although colloids are more expensive, their safety was not seriously questioned until the Cochrane meta-analysis[15] stirred the waters within the critical care community.

After examining 30 RCTs including 1419 patients, the pooled RR of death with albumin administration was reported to be as high as 1.68 (1.26 to 2.23).[15] Based on these data, it was suggested that for every 17 critically ill patients treated with albumin, 1 additional death occurs. These were truly worrisome data considering that the number of septic patients it is necessary to treat (most interventions) in order to save a life is in the range of 5-30. So, if 1 out of 17 patients treated with albumin dies, this can negate the beneficial effects of other interventions. One can imagine the impact this claim had on the use of albumin in ICUs worldwide.

Wilkes and colleagues[2] followed with another meta-analysis of 55 trials involving 3504 patients. They criticized the Cochrane analysis[15] as being seriously flawed, and after examining their own data, they concluded that "overall, no effect of albumin on mortality was detected; any such effect may therefore be small. This finding supports the safety of albumin."

In the context of the confusion created by the conflicting results of these 2 analyses, the completion of the SAFE study was eagerly awaited, and we now know that albumin is at least as safe as saline in nontrauma patients. However, this does not justify the routine use of albumin, as only superiority in mortality reduction over saline would make such a choice reasonable. The crystalloid vs colloid debate is reminiscent of the earlier ARDS debate. In both cases, studies with inherent methodologic problems fostered uncertainty in the critical care community ... not the best days of evidence-based medicine.