Term
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Definition
| the fluid portion of unclotted blood. Composed of 90% water and 10% dissolved constituents such as proteins, carbohydrates, vitamins, etc |
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Term
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Definition
| the fluid portion of clotted blood. During the clotting process, the soluble fibrinogen in plasma is converted to an insoluble fibrin clot matrix. When blood clots, the fluid that is squeezed out around the cellular clot is serum. |
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Term
| Assemble appropriate supplies |
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Definition
- the appropriate vacuum collection tube, needle holder, and needle for the procedure, species, and size of the pt (plasma sampling requires a tube w/ anticoagulant. Serum sampling requires a tube with no anticoagulant)
- one plain red-top tube for serum (this should NEVER be inverted)
- on anticoagulated tube (EDTA or Li heparin) for plasma
- one serum or plasma separator tube |
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Term
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Definition
| - since postprandial samples may produce erroneous results, adult animals should be fasted whenever feasible for at least 12 hrs prior to drawing blood |
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Term
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Definition
- when prepared w/ right supplies, select vein and draw blood
- fill tube to at least 90% capacity
- tubes w/ a vacuum will automatically draw the proper amt of blood
- avoid injecting extra blood into the tube as this may exceed the capacity of the pre-measured anticoagulant to adequately prevent clotting.
- Label the tube immed w/ date, time, clinic, and pt info
- Pre-labeling tube w/ all req’d info, except time, makes it easier to avoid inverting blood in a clot tube
- This reduces the chance of the clot forming with an attachment to the rubber stopper which could disrupt the clot when opening the tube
- Writing on or using pre-printed labels then applying them to the tubes is another good method |
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Term
| Plasma Sample Preparation |
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Definition
- mix the sample w/ anticoagulant by gentle inversion of the tube
- do not shake the sample, as this can cause cell trauma and invalidate the sample
- cover and centrifuge the sample w/in 30 min of collection
- in vitro glycolysis by the blood cells will decrease serum glucose by about 10% per hour if the plasma is not separated from the cells in the 1st 30 min
- each centrifuge is different, follow recommendations
- typically centrifuge at 2000 – 3000 rpm for 10 min
- centrifuging for longer or at higher speeds may result in hemolysis
- check for conditions such as hemolysis, lipemia, and icterus, as these may lead to inaccurate results
- hemolysis is indicated by pink or red plasma and may be due to trauma of the cells during venipuncture, poor handling of the sample, or dz processes in the pt
- lipemia results in a cloudy appearance of the plasma and is normally due to insufficient fasting prior to sample collection
- icteric plasma is yellow and may indicate liver dz |
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Term
| - in vitro glycolysis by the blood cells will decrease serum glucose by |
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Definition
| - in vitro glycolysis by the blood cells will decrease serum glucose by about 10% per hour if the plasma is not separated from the cells in the 1st 30 min |
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Term
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Definition
| is indicated by pink or red plasma and may be due to trauma of the cells during venipuncture, poor handling of the sample, or dz processes in the pt |
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Term
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Definition
| - lipemia results in a cloudy appearance of the plasma and is normally due to insufficient fasting prior to sample collection |
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Term
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Definition
- icteric plasma is yellow and may indicate liver dz
- w/ a disposable pipette or capillary tube, harvest the fluid plasma, and place it into a plain, clean transparent tube
- ensure that the sample in not contaminated w/ cells from the bottom of the tube
- if this occurs, the serum can be spun again in the new tube and plasma removed once again with a new pipette
- sample should be clear and colorless
- if not, make note of any abnormalities in color or clarity
- label tube with date, time, pt and clinic info, best with a sharpie
- serum samples not processed immediately should be refrigerated until testing begins if w/in 72 hrs.
- for longer periods of storage, serum samples may be frozen at -20 degrees celcius |
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Term
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Definition
- allow the serum tube to clot prior to centrifugation. Don’t wait too long, separate the serum w/in 30 min since the RBCs will continue to undergo some metabolic processes, which could alter your lab results.
- Don’t shake or mix w/ anticoagulants
- Gently separate the clot from the container by “rimming” or running, a wooden applicator stick around the wall of the container between the clot and the wall
- Centrifuge the tube at the correct speed and time according to the manufacturer’s instructions. Typically 2000 – 3000 rpm for 10 min. for longer or higher speeds may result in hemolysis.
- A critical step after centrifuging is to observe for hemolysis, lipemia, and icterus, as these may lead to inaccurate results
- Harvest the serum from the clot using a capillary tube or disposable pipette and transfer it into a plain, clean transparent tube. Ensure that the sample is not contaminated with cells from the bottom of the tube. The sample should be clear and colorless. If not, record the abnormal findings in the pt’s medical record and lab report. Tell the vet as some of these may indicate serious dz
- Label tube w/ date, time, pt’s name, and clinic info
- Refrigerate or freeze the sample if not processed immediately |
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