blood preservation Flashcards
how to choose the right blood tube
-what test to perform
-which blood compartment is the substrate in (eg virus in plasma)
-how fast does this substrate metabolise (wg glucose: oxidative fermentation by bac)
what ions are rewuired for clotting
calcium ions
tell me about EDTA (purple) tube
EDTA coated on walls (stops calcium ions from forming clots)
purpose: anticoagulant of choice for CBC and blood smears
can sometimes cause platelet clumping (gets activated)
heparin tube (green)
contains lithium heparin that binds to enzyme inhibitor antithrombin and activates it-> AT will inactive thrombin-> no clotting
-used for biochemistry tests (organ functions)
citrate tube (blue)
contains sodium citrate
used for: coagulation tests (stops blood from clotthing, can test for enzymes invloved in blood clotting process)
-anti-coaggulant in blood transfusion bags
plain tube (red)
-no additive
-allows blood to clot ( 4-8 mins)
-ill be spun down to collect serum
serum seperated tube (yellow top)
-allows blood to clot
contains a gel that seperates solid and liquid components of blood when centrifuges (sperste cltted blood to obtain serum)
-better than red tube because ensure no blood cells are accidentally collected when collecting serum)
storage of sample before processing
-analyse within 3 hrs
if not refrigerate at 4 degrees to minimise hemolysis (RBC get destroyed) and degenerative changes
what is anemia
-decrease in RBC number
-decrease i haemoglobin concentration
what are the cuases of anemia
-inadaquate production of RBC (bone marrow disease- RBC produced in bone marrow)
-excess loss of RBC (bleeding)
-excessive destruction of RBC (hemolyic anemia)
what happens during erythropoiesis (RBC life cycle)
-cells become smaller
-nuclei become smaller and eventually disappear
-cytoplasm changes colour from blue to orange (rna lost, haemoglobin formed)
what are baby RBC know ass
reticulocytes
tell me about how reticulocytes look like
-no nucleus
-tend to appear more basophillic and larger than adult RBC
-contains RNA (causes blue colour)
what does it mean when reticulocytes appea on blood smear
reticulocytes are a hallmark of an erythrocyte (adult RBC) regenreative response (means they are trying to produce more RBC)
sign of regenativr anemia ( body is responding to the anemia by producing more RBC)
they take 24 hrs to mature once in ciculation, is not as effective as erythrocytes
what are macrocytes
-large immature RBC )eg reticulocytes and everything else before that
-seen in regenetive anemia
what are microcytes
small erythrocyes (old and tired, grandpa rbcs)
-seen in iron- defficient anemia
what does anisocytosis
(aniso= variation)
variation in size of erythrocytes (presence of both macrocytes and microcytes among normocytes)