MLT 1003 : ORIENTATION TO CLINICAL LABORATORY SCIENCE
Name : Sherry Jenkins
Date:___________
1. There are 15 ml of saline in a test tube. You add 3 ml of serum.
following: 1 point each
A. Saline to Serum Ratio = 15ml:3ml = 5:1
B. Saline to total Volume Ratio = 15ml:(15ml+3ml)=15ml:18ml = 5:6
C.Serum to Saline Ratio= 3ml:15ml =1:5
D.Total Volume to serum ratio = (15ml+3ml):3ml = 18ml:3ml = 6:1
E..Serum Dilution = 3ml:(3ml+15ml) = 3ml:18ml = 1:6
Give the
2. Give the serum to saline ratio for the following dilutions:
A. 1/27 => serum : saline = 1: (27-1)=1:26
B. 16/64 => serum : saline = 16: (64-16)=16:48=1:3
C. 6/24 => serum : saline = 6: (24-6)=6:18=1:3
3. What are the serum dilutions for the following: 1 Point each
A.
B.
2 ml serum, 12 ml saline =>serum dilution = 2ml: (2ml+12ml)=2ml:14ml=1:7
2 ml serum, 11 ml saline,
7 ml ETOH
=> serum dilution = 2ml: (2ml+11ml+7ml)=2ml:20ml=1:10
C. 10 ml serum , 90 ml saline=> serum dilution =10ml: (10ml+90ml)=10ml:100ml=1:10
D.
0.2 ml serum, 0.8 ml saline
4 ml reagent A, 5 ml reagent B
=> serum dilution = 0.2ml: (0.2ml+0.8ml+4ml+5ml) = 0.2ml:10ml = 1:50
4.
2 ml of serum is diluted with 18 ml water:
A. What the serum to water ratio: 2ml:18ml = 1:9
B. What is the dilution of the serum? 2ml: (2ml+18ml)=2ml :20ml = 1:10
5.
20 ml of saline is added to 5 ml of serum:
A. What is the serum dilution? 5ml: (5ml+20ml)=5ml:25ml=1:5
B. What is the serum to saline ratio? 5ml:20ml = 1:4
The following questions are worth 2 points each : SHOW ALL WORK
6. If you add 48 ml saline to 2 ml of serum, what is the dilution.
Dilution = serum: total volume = 2ml: (2ml+48ml)=2ml:50ml = 1:25
7. What is the final dilution of an unknown specimen using 0.3 ml of blood, and
mixing it with 3.3 ml of water and 1.0 ml of reagent , and 1.6 ml of ETOH?
Dilution = blood: total volume = 0.3ml: (0.3ml+3.3ml+1.0ml+1.6ml)=0.3ml:6.2ml=3:62
8. The following quantities are placed in a test tube ; 0.1 ml sample, 3.0 ml
diluent, 0.4ml reagent #1, and 0.5 of reagent #2. What is the final dilution of the
sample?
Dilution = sample: total volume =0.1ml: (0.1ml+3.0ml+0.4ml+0.5ml)=0.1ml:4ml=1:40
9. 0.2 ml of serum is obtained and diluted 1/20. What is the amount of diluent
added to the serum?
Let add x ml diluent, then
Dilution = serum: total volume = 0.2ml: (0.2ml + xml)=1:20 => 0.2ml+xml = 0.2ml*20
=>0.2ml+xml = 4ml =>x = 3.8ml
10. A total of 240 ml of a 1/4 dilution is to be prepared from concentrated H2S04.
How much concentrated H2S04 is required to make the solution?
It is (total volume)*dilution = 240ml*1/4 = 60ml,
So 60ml concentrated H2S04 is required to make the solution
11. How much of a 1/25 solution can be made from 12.5 ml of concentrated solution?
Let xml 1/25 solution can be made from 12.5 ml of concentrated solution, then
xml*1/25 = 12.5ml => x = 12.5ml*25 => x = 312.5ml
12. How would you make 500 ml of a 4/20 dilution of bleach?
Amount of concentrated bleach = (total volume)*dilution = 500ml * 4/20 = 100ml
So with 100ml concentrated bleach, add 500ml-100ml = 400ml diluent, then get 500 ml
of a 4/20 dilution of bleach.
13. How much serum would be present in 50 ml of a 1/9 dilution?
50ml*1/9 = 5.56ml (approximate)
14.What would the total volume of a solution be if you started out with 8 ml
of urine and made a 2/18 dilution?
Let total volume of a solution is xml, then Dilution = urine: total volume
=> 2/18 = 8ml:xml =>x = 72ml
15. You have 500 ml of a 1/25 dilution of serum in saline. How much serum is
present in that 500 ml?
500ml*1/25 = 20 ml
16. A 1/4 dilution is further diluted by adding 2.5 ml of water to 0.5 ml of the
original dilution. What is the concentration of the resulting solution?
the concentration of the resulting solution = original dilution* dilution factor
=1/4*[0.5m: (0.5ml+2.5ml)] = 1/4*[1/6] = 1/24
17. A 10% solution is diluted 1/200. What is the final concentration of the
solution?
the concentration of the resulting solution = original dilution* dilution factor
=10%*1/200 = 1/10*(1/200) = 1/2000
18. A 35% solution is diluted 1/50. What is the final concentration of the
solution?
the concentration of the resulting solution = original dilution* dilution factor
= 35% * (1/50) = 7/20*(1/50) = 7/1000
19. 10 ml of 10% HCL is diluted 1/40 . What is the volume of the solution?
volume of the solution = solvent volume/dilution = 10ml/(1/40) = 400ml
A. What is the concentration of the solution ?
the concentration of the resulting solution = original dilution* dilution factor
=10%*(1/40) = 1/10*(1/40)=1/400
20.
A multiple dilution was performed. The sample was diluted 1/2 , 1/4,
and 1/5. What is the final dilution of the sample?
1/10,
the final dilution of the sample = original dilution* dilution factor1 * dilution
factor2* dilution factor3 *dilution factor4 = 1*(1/2) *(1/4)*(1/10)*(1/5) = 1/400
A.
What is the concentration of "X" in tube 3 if in the original tube the
concentration of "X" was 1000 mg?
the final dilution of the sample in tube 3 = original dilution* dilution factor1 *
dilution factor2* dilution factor3 = 1*(1/2) *(1/4)*(1/10) = 1/80, so
the concentration of "X" in tube 3 = concentration of “X” in original tube * the
final dilution of the sample in tube 3 = 1000mg*1/80 = 12.5mg
21.
A CMV antibody titer was performed on a 2 week old infant girl. The babies
serum was tested with CMV antigen in the following sequence. Neat- , 1/2,
1/4, 1/8, and 1/16 . Positive reactions occured in the neat , 1/2, 1/4,
and 1/8 tubes. What is the babies CMV titer?
the babies CMV titer = 1*(1/2)*(1/4)*(1/8) = 1/64
22. A rubella antibody titer was performed on a 45 year old man . The dilution
sequence was performed in a microtiter plate by first adding 25 ul of serum to 75
ul of diluent in well#1. 25 ul of the first dilution was added to 75 ul of diluent
in well #2. 50 ul from well 2 was added to 50 ul of diluent in well#3. Wells 4-12
were serially diluted in two-fold dilutions. What would be the dilution in well #6?
Dilution factor of well#1 = 25 ul/(25ul+75ul) = 25ul/100ul = 1/4
Dilution factor of well#2 = 25 ul/(25ul+75ul) = 25ul/100ul = 1/4
Dilution factor of well#3 = 50 ul/(50ul+50ul) = 50ul/100ul = 1/2 , so
the dilution in well #6 = Dilution factor of well#1* Dilution factor of well#2*
Dilution factor of well#3* Dilution factor of well#4* Dilution factor of well#5*
Dilution factor of well#6 = (1/4)*(1/4)*(1/2)*(1/2)*(1/2)*(1/2) = 1/256