W3 specimen prep

Question 1

what do MLAs do to prepare specimens?

Answer 1

allow time to clot. Centrifugation. separating serum or plasma from cells and or making an aliquot to share specimens

Question 2

what does a centrifuge do/what is it needed for?

Answer 2

separate plasma or serum from formed elements (cells-rbc,wbc)
its important to note all samples must be capped in order to -prevent spills -prevent the development of aerosols -possible evaporation -possible exogenous contamination of specimen

Question 3

specimens received in ice water

Answer 3

are centrifuged in a 4 degrees refrigerated centrifuge and these would be something like ammonia or lactate

Question 4

RPM

Answer 4

revolutions per minute

Question 5

RCF

Answer 5

relative centrifugal force and this can be converted into rpm because the speed and time could change related to the diameter

Question 6

serum samples and the centrifuge

Answer 6

gold or red, SST
NEED TIME TO CLOT BEFORE CENTRIFUGE- if clotting incomplete fibrin left in serum may cause problems with instrument
Plain red- 30-60 minutes
sst-30 minutes
clot activator tubes- usually used for stat and have enzyme at the bottom that forms thrombin only needs 5-15 minutes.
always set a timer
-* set serum tubes for 10 minutes 1000-1300 RCF *for gel and non gel tubes – this creates complete separation of serum from cells

Question 7

plasma samples and centrifuge

Answer 7

-contain anticoagulant- don’t need to sit
10 minutes 1000-1300 ref
-blue tops (sodium citrate) also centrifuged-plasma not taken off -15 minutes at 1500 rcf

Question 8

microtainer tubes and centrifuge

Answer 8

same clotting times for serum -placed in small ones adapter still need to be balanced
gel tubes-90 seconds 6000-15000 rcf
non-gel-3 minutes 2000 rcf

Question 9

whole blood and centrifuge

Answer 9

edta lab are actually never centrifuged and can be delivered to hem

Question 10

why do we need to centrifuge specimens right away

Answer 10

there is 25 more potassium in rbc than serum delay= movement of potassium into plasma or serum and this messes up some tests especially if its for calcium, also rbc start to metabolize glucose in blood

• • should be spun before 2 hours
• • left out of fridge for 8

Question 11

failure of migration of gel

Answer 11

• • do not re-spin
    1. aliquot serum or plasma into new labelled tube
    2. spin aliquot (there will be a button or a couple of rbc at bottom)
    3. aliquot cell free serum or plasma into a new labelled aliquot tube and use that one

Question 12

what to do if there are fibrin strands and what does this mean

Answer 12

usually it means you centrifuged the specimen to early and you need to transfer the serum to an aliquot tube and respin

Question 13

rubber stopper removal

Answer 13

never recap-you can get them mixed up, use new caps or usually use parafilm

Question 14

what is on an aliquot tube?

Answer 14

same patient demographics-name, dob, phn

• accession number
• tests to be done
• type of specimen(pst plasma, Nacit plasma)
• volume
• • usually lis reprint label, if not you would write it out.
• • make sure only the tests that is required to be run on the aliquot remains on the label– cross out the other tests

Question 15

Aliquot technique

Answer 15

1. determine number of aliquot tubes and volume of specimen required (if two tests are done chem then one tube required but if ones in hem and one is in hem then two tubes required)
2. label aliquot tubes –**place in rack behind appropriate specimen tube
3. check patient and testing information on label to aliquot label —work left to right from lowest accession number to highest
4. remove stopper, hold both tubes in left hand and check labels again
5. ransfer fluid using a pipette
6. cover both tubes immediately with parafilm or new cap
7. check labels again hem

Question 16

hematology

Answer 16

lavender EDTA

no centrifuging

Question 17

coagulation

Answer 17

light blue
sodium citrate plasma tubes
fill 90% capacity
may or may not need to be spun

Question 18

chemistry and special chemistry

Answer 18

check if red has gel

*sst- red or gold
majority of them testing
need to wait before centrifuging
*pst- mint
centrifuged right away - stats usually collected in these tubes
—check plasma sample suitable. check what is in heparin -lithium most common but also there is sodium and ammonium
*plain red top tube- glass or plastic can always use in place of an sst but you can’t use an sst instead of red top

Question 19

transfusion medicine

Answer 19

edta 6ml lav
centrifuged for TM labs
type and screen
tm labs prefer to centrifuge their own tubes

Question 20

stat sample

Answer 20

always announce to the technologist if it is stat