mixing studies

Question 1

how is substitution studies performed?

Answer 1

by mixing correction reagents with patient’s plasma and then performing the PT and/or APTT

Question 2

what are the mixing correction reagents?

Answer 2

adsorbed plasma and aged serum

Question 3

why is substitution studies performed?

Answer 3

to identify a specific factor deficiency

Question 4

the following factors that are rich in adsorbed plasma:

Answer 4

Factor II, V, VIII, XI, XII

Question 5

the following factors that are rich in aged serum:

Answer 5

Factor VII, IX, X, XI, XII

Question 6

factors that are used in mixing studies

Answer 6

Factor XI, XII

Question 7

what is considered as PT reagent?

Answer 7

tissue thromboplastin

Question 8

what is considered as APTT

Answer 8

partial thromboplastin with activator and CaCl2

Question 9

what are the reagents used in mixing studies?

Answer 9

APTT, PT, and 0.85% w/v Sodium chloride

Question 10

specimen for mixing studies

Answer 10

fresh plasma from citrated whole blood

Question 11

first step of the procedure

Answer 11

Perform PT and APTT with patient’s undiluted plasma and normal control plasma.

Question 12

TRUE OF FALSE: the control sample can change its result ranges throughout the procedure

Answer 12

FALSE: the result ranged should be within normal throughout the procedure.

Question 13

second step of the procedure

Answer 13

perform substitution test on the procedure (PT/APTTA) on the abnormal results.

Question 14

how to rule out the presence of inhibitor?

Answer 14

test the circulating anticoagulants should have been previously performed.

Question 15

continuation of second step of the procedure

Answer 15

Perform PT and APTT with the following mixtures

Question 16

following mixtures: 2.1-2.2

Answer 16

2.1 = 0.1ml patient’s plasma + 0.1 ml 0.85% NaCl
2.2 = 0.1 ml control plasma + 0.1 ml 0.85% NaCl

Question 17

following mixtures: 2.3-2.4

Answer 17

adsorbed plasma

Question 18

following mixtures: 2.5-2.6

Answer 18

aged serum

Question 19

normal in APTT

Answer 19

1 and 6

Question 20

normal in PT

Answer 20

1-3, 7

Question 21

normal PT and APTT

Answer 21

no deficiency

Question 22

corrected APTT in both adsorbed plasma and aged serum

Answer 22

deficiency in XI/XII

Question 23

APTT (adsorbed) = NC
APTT (aged) = C
normal = PT

Answer 23

IX deficiency

Question 24

APTT/PT = A
APTT/PT (adsorbed) = NC
APTT/PT (aged) = C

Answer 24

X deficiency

Question 25

APTT/PT = A APTT/PT (adsorbed) = C APTT/PT (aged) = NC

Answer 25

V deficiency

Question 26

PT= abnormal (adsorbed) = C serum = NC

Answer 26

VII

Question 27

APTT = A adsorbed = C aged = NC

Answer 27

VIII

Question 28

APTT/PT = A AP AND AS = NC

Answer 28

II

Question 29

how to obtain platelet-poor plasma?

Answer 29

centrifuge unopened whole blood specimens at 2500rpm for 20 minutes

Question 30

where does the centrifuged plasma stored?

Answer 30

labeled plastic tube and place in water bath

Question 31

how many hours is specimen should be tested?

Answer 31

2 hours

Question 32

how many mg of barium sulfate should be added in 1ml plasma?

Answer 32

50mg

Question 33

first step of barium sulfate preparation

Answer 33

Add 50mg of barium sulfate to 1ml plasma

Question 34

2nd step of barium sulfate preparation

Answer 34

incubate at 37c for 15 minutes with frequent mixing

Question 35

3rd step of barium sulfate adsorption

Answer 35

centrifuge at 2k rpm to obtain a clear supernatant fluid

Question 36

how much volume of aluminum hydroxide to 4ml distilled water?

Answer 36

1gm

Question 37

how much volume of suspension is added to the citrated plasma?

Answer 37

1 volume of suspension to 9 volumes of citrated plasma

Question 38

how long is the incubation of aluminum hydroxide?

Answer 38

5 minutes