Question 1

Which of the following expressions defines the dilution ratio of a sample?

Accepted Answer

A)  $ \frac{\mathrm{V}_{\text {initial }}}{\mathrm{V}_{\text {final }}}=\mathrm{C}_{\text {final }} $ 
B)  $ \frac{V_{\text {initial }}}{V_{\text {funal }}}=\frac{C_{\text {final }}}{C_{\text {inutial }}} $ 
C)  $ \frac{\mathrm{V}_{\text {initial }}}{\mathrm{V}_{\text {funal }}}=\frac{\mathrm{C}_{\text {initial }}}{\mathrm{C}_{\text {final }}} $ 
D)  $ \frac{V_{\text {inuitial }}}{V_{\text {funal }}}=V_{\text {final }} $ 
A)  $ \frac{\mathrm{V}_{\text {initial }}}{\mathrm{V}_{\text {final }}}=\mathrm{C}_{\text {final }} $ 
B)  $ \frac{V_{\text {initial }}}{V_{\text {funal }}}=\frac{C_{\text {final }}}{C_{\text {inutial }}} $ 
C)  $ \frac{\mathrm{V}_{\text {initial }}}{\mathrm{V}_{\text {funal }}}=\frac{\mathrm{C}_{\text {initial }}}{\mathrm{C}_{\text {final }}} $ 
D)  $ \frac{V_{\text {inuitial }}}{V_{\text {funal }}}=V_{\text {final }} $ B

Question 2

Which of the following must be done in order to create a standard curve from a single vial of a known concentration of glucose?

Accepted Answer

A)  Additional known quantities of glucose must be added to the vial. 
B)  Other vials of known glucose concentrations must be obtained. 
C)  Serial dilutions must be made. 
D)  The vial must be tested daily for 10 days. 
A)  Additional known quantities of glucose must be added to the vial. 
B)  Other vials of known glucose concentrations must be obtained. 
C)  Serial dilutions must be made. 
D)  The vial must be tested daily for 10 days. C

Question 3

A laboratory technician performs an antibody titer.A reaction is detected in every dilution from 1:2 up to and including 1:64.What does this tell the technician about the amount of antibody present?

Accepted Answer

A)  The amount of antibody in the original sample can be calculated by multiplying 64 by the total number of tubes used in the dilution. 
B)  The antibody is able to detectably bind all the antigen present in a sample when the concentration of antibody is at a 1:64 dilution. 
C)  There is enough antibody in the serum to react visibly with antigen when diluted 64-fold, but not at 128-fold or more. 
D)  All of the above 
A)  The amount of antibody in the original sample can be calculated by multiplying 64 by the total number of tubes used in the dilution. 
B)  The antibody is able to detectably bind all the antigen present in a sample when the concentration of antibody is at a 1:64 dilution. 
C)  There is enough antibody in the serum to react visibly with antigen when diluted 64-fold, but not at 128-fold or more. 
D)  All of the above C

Question 4

The initial volume of a sample is 100 μL.It is diluted with saline by a factor of 4.The final volume is 400 μL.Testing the diluted sample finds an analyte concentration of 25 μg/mL.Which of the following expressions can be used to calculate the initial analyte concentration of this sample?

Accepted Answer

A)  $ \frac{(400 \mu \mathrm{L})\left(\frac{25 \mu g}{\mathrm{~mL}}\right)}{100 \mu \mathrm{L}} $ 
B)  $ \frac{(100 \mu L)\left(\frac{25 \mu g}{m L}\right)}{400 \mu L} $ 
C)  $ \frac{(400 \mu \mathrm{L})(100 \mu \mathrm{L})}{\frac{25 \mu \mathrm{g}}{\mathrm{mL}}} $ 
D)  $ \frac{\text { (2) }\left(\frac{25 \mu g}{m L}\right)}{400 \mu \mathrm{L}} $ 
A)  $ \frac{(400 \mu \mathrm{L})\left(\frac{25 \mu g}{\mathrm{~mL}}\right)}{100 \mu \mathrm{L}} $ 
B)  $ \frac{(100 \mu L)\left(\frac{25 \mu g}{m L}\right)}{400 \mu L} $ 
C)  $ \frac{(400 \mu \mathrm{L})(100 \mu \mathrm{L})}{\frac{25 \mu \mathrm{g}}{\mathrm{mL}}} $ 
D)  $ \frac{\text { (2) }\left(\frac{25 \mu g}{m L}\right)}{400 \mu \mathrm{L}} $

Question 5

When is it advisable to perform a serial dilution rather than a simple dilution?

Accepted Answer

A)  When a sample must be divided into several tubes or vessels 
B)  When a very large dilution is required 
C)  When multiple samples require dilution 
D)  All of the above 
A)  When a sample must be divided into several tubes or vessels 
B)  When a very large dilution is required 
C)  When multiple samples require dilution 
D)  All of the above

Question 6

How is antibody titer determined?

Accepted Answer

A)  Calculating the ratio of antibody to antigen in the highest possible sample dilution in which all antigen is bound 
B)  Measuring highest possible dilution where antibody is able to bind antigen 
C)  Measuring the minimum possible concentration of antibody necessary to bind all antigen present in a sample 
D)  Taking the reciprocal of the highest sample dilution ratio at which antibody is detectable 
A)  Calculating the ratio of antibody to antigen in the highest possible sample dilution in which all antigen is bound 
B)  Measuring highest possible dilution where antibody is able to bind antigen 
C)  Measuring the minimum possible concentration of antibody necessary to bind all antigen present in a sample 
D)  Taking the reciprocal of the highest sample dilution ratio at which antibody is detectable

Question 7

What does the term "tube dilution" refer to?

Accepted Answer

A)  The amount of diluent in a tube before sample is added 
B)  The dilution factor of each tube in a serial dilution 
C)  The number of tubes used in a serial dilution 
D)  The total volume of diluent used in a serial dilution 
A)  The amount of diluent in a tube before sample is added 
B)  The dilution factor of each tube in a serial dilution 
C)  The number of tubes used in a serial dilution 
D)  The total volume of diluent used in a serial dilution

Question 8

A sample of turbid knee fluid arrives in your laboratory and needs to be analyzed for the presence of white blood cells (WBC).An initial test reveals that the WBC concentration is higher than the upper limit of the automated blood analyzer.Which of the following should be done in order to achieve an accurate reading?

Accepted Answer

A)  Extrapolate the concentration from a standard curve. 
B)  Obtain another sample. 
C)  Order a more sensitive machine. 
D)  Perform a dilution of the sample. 
A)  Extrapolate the concentration from a standard curve. 
B)  Obtain another sample. 
C)  Order a more sensitive machine. 
D)  Perform a dilution of the sample.

Question 9

A urine sample is diluted 1:4 before testing.Testing indicates that the concentration of protein present is 10 μg.What is the true concentration of protein in the urine?

Accepted Answer

A)  2.5 μg 
B)  10 μg 
C)  20 μg 
D)  40 μg 
A)  2.5 μg 
B)  10 μg 
C)  20 μg 
D)  40 μg

Question 10

What is a serial dilution?

Accepted Answer

A)  A dilution of a series of samples 
B)  A dilution that must always be performed 
C)  A sample that requires more than one dilution 
D)  A series of small dilutions 
A)  A dilution of a series of samples 
B)  A dilution that must always be performed 
C)  A sample that requires more than one dilution 
D)  A series of small dilutions

Question 11

Because the tube dilution is the same for all tubes in a serial dilution,the sample dilution for a given tube can be determined using which equation (in all cases N is the number of the tube in the sequence)?

Accepted Answer

A)  $ D_{\text {sample }}=\left(D_{\text {tube }}\right) N $ 
B)  $ D_{\text {Sample }}=\left(D_{{tube }}\right)^{N} $ 
C)  $ D_{\text {sample }}=\frac{V_{\text {tube }}}{N} $ 
D)  $ D_{\text {sample }}=\frac{N}{V_{\text {tube }}} $ 
A)  $ D_{\text {sample }}=\left(D_{\text {tube }}\right) N $ 
B)  $ D_{\text {Sample }}=\left(D_{{tube }}\right)^{N} $ 
C)  $ D_{\text {sample }}=\frac{V_{\text {tube }}}{N} $ 
D)  $ D_{\text {sample }}=\frac{N}{V_{\text {tube }}} $

Question 12

A laboratory technician is given a blood sample and asked to calculate the concentration of dopamine.The first test reveals that the concentration of dopamine falls outside the reliable range for the testing method.He adds 100 μL saline solution to 100 μL of the sample and retests the sample.How does the concentration of dopamine in the diluted sample compare to the concentration of dopamine in the original sample?

Accepted Answer

A)  The concentration in the diluted sample is one-half that of the original sample. 
B)  The concentration in the diluted sample is one hundred times that of the original sample. 
C)  The concentration in the diluted sample is one-tenth that of the original sample. 
D)  The concentration in the diluted sample is twice that of the original sample. 
A)  The concentration in the diluted sample is one-half that of the original sample. 
B)  The concentration in the diluted sample is one hundred times that of the original sample. 
C)  The concentration in the diluted sample is one-tenth that of the original sample. 
D)  The concentration in the diluted sample is twice that of the original sample.

Question 13

A laboratory technician is asked to determine the concentration of LDL present in a blood sample.The initial test finds the concentration of LDL to be outside the reliable range for the testing method.Accordingly,she dilutes the blood sample in 100 μL distilled water (dH₂O).What is the diluent in this scenario?

Accepted Answer

A)  The blood-dH₂O mixture 
B)  The blood sample 
C)  The dH₂O 
D)  The LDLs 
A)  The blood-dH₂O mixture 
B)  The blood sample 
C)  The dH₂O 
D)  The LDLs

Question 14

A sample ready for analysis is a 1:2 dilution.Which of the following is true about this sample?

Accepted Answer

A)  The volume of the sample is decreased by a factor of 2, and the concentration is decreased by 2. 
B)  The volume of the sample is decreased by a factor of 2, and the concentration is increased by 2. 
C)  The volume of the sample is increased by a factor of 2, and the concentration is decreased by 2. 
D)  The volume of the sample is increased by a factor of 2, and the concentration is increased by 2. 
A)  The volume of the sample is decreased by a factor of 2, and the concentration is decreased by 2. 
B)  The volume of the sample is decreased by a factor of 2, and the concentration is increased by 2. 
C)  The volume of the sample is increased by a factor of 2, and the concentration is decreased by 2. 
D)  The volume of the sample is increased by a factor of 2, and the concentration is increased by 2.

Question 15

A urine sample is diluted 1:3 before testing.The test results identify 50 μg phenylpyruvate.What is the dilution factor that the result must be multiplied by to determine the true concentration of phenylpyruvate in the urine?

Accepted Answer

A)  1 
B)  3 
C)  10 
D)  50 
A)  1 
B)  3 
C)  10 
D)  50

Question 16

A 100 μL sample of blood is diluted with 200 μL saline solution.What is the dilution ratio of the sample after dilution?

Accepted Answer

A)  1:2 
B)  1:3 
C)  1:4 
D)  1:10 
A)  1:2 
B)  1:3 
C)  1:4 
D)  1:10

Question 17

Which of the following is a reason to make dilutions?

Accepted Answer

A)  The concentration of a given analyte is higher than the upper limit of the method to be used. 
B)  The concentration of analyte falls below the normal expected range. 
C)  The sample does not contain the desired analyte to be measured. 
D)  The type of analyte is unable to be read using the desired method or equipment. 
A)  The concentration of a given analyte is higher than the upper limit of the method to be used. 
B)  The concentration of analyte falls below the normal expected range. 
C)  The sample does not contain the desired analyte to be measured. 
D)  The type of analyte is unable to be read using the desired method or equipment.

Question 18

Which of the following equations defines the tube dilution in a serial dilution?

Accepted Answer

A)  $ \frac{V_{\text {sam ple }}}{V_{\text {sample }}+V_{\text {diluent }}} $ 
B)  $ \frac{\text { Number of tubes }}{\mathrm{V}_{\text {sample }}+\mathrm{V}_{\text {dilent }}} $ 
C)  $ \frac{V_{\text {sample }}}{V_{\text {sample }} \times \text { Number of tubes }} $ 
D)  $ \frac{V_{\text {sample }}}{{\text {Number of tubes }} \div \text {V}{ diluent}} $ 
A)  $ \frac{V_{\text {sam ple }}}{V_{\text {sample }}+V_{\text {diluent }}} $ 
B)  $ \frac{\text { Number of tubes }}{\mathrm{V}_{\text {sample }}+\mathrm{V}_{\text {dilent }}} $ 
C)  $ \frac{V_{\text {sample }}}{V_{\text {sample }} \times \text { Number of tubes }} $ 
D)  $ \frac{V_{\text {sample }}}{{\text {Number of tubes }} \div \text {V}{ diluent}} $

Question 19

A technologist picks up a serum sample with a label indicating it is a 1:4 dilution.What does this tell the technologist about the sample?

Accepted Answer

A)  The concentration of any substance within the sample is 0.01 times its real value. 
B)  The concentration of any substance within the sample is one-fourth its real value. 
C)  The concentration of any substance within the sample is 100 times its real value. 
D)  The concentration of any substance within the sample is four times its real value. 
A)  The concentration of any substance within the sample is 0.01 times its real value. 
B)  The concentration of any substance within the sample is one-fourth its real value. 
C)  The concentration of any substance within the sample is 100 times its real value. 
D)  The concentration of any substance within the sample is four times its real value.

Question 20

What is an antibody titer?

Accepted Answer

A)  The amount of antibody bound to a specific antigen in a sample 
B)  The amount of antibody present in a serum against a particular antigen 
C)  The concentration of all antibodies present in a sample 
D)  The volume of serum composed of antibodies 
A)  The amount of antibody bound to a specific antigen in a sample 
B)  The amount of antibody present in a serum against a particular antigen 
C)  The concentration of all antibodies present in a sample 
D)  The volume of serum composed of antibodies

Which of the following expressions defines the dilution ratio of a sample?

Which of the following must be done in order to create a standard curve from a single vial of a known concentration of glucose?

A laboratory technician performs an antibody titer.A reaction is detected in every dilution from 1:2 up to and including 1:64.What does this tell the technician about the amount of antibody present?

The initial volume of a sample is 100 μL.It is diluted with saline by a factor of 4.The final volume is 400 μL.Testing the diluted sample finds an analyte concentration of 25 μg/mL.Which of the following expressions can be used to calculate the initial analyte concentration of this sample?

When is it advisable to perform a serial dilution rather than a simple dilution?

How is antibody titer determined?

What does the term "tube dilution" refer to?

A urine sample is diluted 1:4 before testing.Testing indicates that the concentration of protein present is 10 μg.What is the true concentration of protein in the urine?

What is a serial dilution?

Because the tube dilution is the same for all tubes in a serial dilution,the sample dilution for a given tube can be determined using which equation (in all cases N is the number of the tube in the sequence)?

A sample ready for analysis is a 1:2 dilution.Which of the following is true about this sample?

A urine sample is diluted 1:3 before testing.The test results identify 50 μg phenylpyruvate.What is the dilution factor that the result must be multiplied by to determine the true concentration of phenylpyruvate in the urine?

A 100 μL sample of blood is diluted with 200 μL saline solution.What is the dilution ratio of the sample after dilution?

Which of the following is a reason to make dilutions?

Which of the following equations defines the tube dilution in a serial dilution?

A technologist picks up a serum sample with a label indicating it is a 1:4 dilution.What does this tell the technologist about the sample?

What is an antibody titer?

Arithmetic and Algebra

Exponential Notation & Logarithms

Rounding and the Significance of Figures

Systems of Measurement

Solutions and Concentrations

Proportionality, Graphs, and Rates of Change

Statistics

Chemistry

Hematology

Quality Control

Method Evaluation

Filters

Exam 6: Dilutions

Which of the following expressions defines the dilution ratio of a sample?

Which of the following must be done in order to create a standard curve from a single vial of a known concentration of glucose?

A laboratory technician performs an antibody titer.A reaction is detected in every dilution from 1:2 up to and including 1:64.What does this tell the technician about the amount of antibody present?

The initial volume of a sample is 100 μL.It is diluted with saline by a factor of 4.The final volume is 400 μL.Testing the diluted sample finds an analyte concentration of 25 μg/mL.Which of the following expressions can be used to calculate the initial analyte concentration of this sample?

When is it advisable to perform a serial dilution rather than a simple dilution?

How is antibody titer determined?

What does the term "tube dilution" refer to?

A urine sample is diluted 1:4 before testing.Testing indicates that the concentration of protein present is 10 μg.What is the true concentration of protein in the urine?

What is a serial dilution?

Because the tube dilution is the same for all tubes in a serial dilution,the sample dilution for a given tube can be determined using which equation (in all cases N is the number of the tube in the sequence)?

A sample ready for analysis is a 1:2 dilution.Which of the following is true about this sample?

A urine sample is diluted 1:3 before testing.The test results identify 50 μg phenylpyruvate.What is the dilution factor that the result must be multiplied by to determine the true concentration of phenylpyruvate in the urine?

A 100 μL sample of blood is diluted with 200 μL saline solution.What is the dilution ratio of the sample after dilution?

Which of the following is a reason to make dilutions?

Which of the following equations defines the tube dilution in a serial dilution?

A technologist picks up a serum sample with a label indicating it is a 1:4 dilution.What does this tell the technologist about the sample?

What is an antibody titer?

Arithmetic and Algebra

Exponential Notation & Logarithms

Rounding and the Significance of Figures

Systems of Measurement

Solutions and Concentrations

Proportionality, Graphs, and Rates of Change

Statistics

Chemistry

Hematology

Quality Control

Method Evaluation

Filters