Preparing Samples and Recording Results

Instructions & Working Table (Javascript)
Preparing a plot
Cholesterol Example
See Worksheet 2
Back to MV - The Linearity or Reportable Range Experiment

Step 1: Preparing Samples and Recording Results

Pool 1:
(0%)
No preparation necessary (use zero or very low sample). Assay in triplicate.
Record Measurements: 1: , 2: , 3:
Mean of pool 1: ((1,2,3)/3) 
Pool 2:
(25%)
Combine 3 parts Pool 1 and 1 part Pool 5 (e.g. 1.5 ml and 0.5 ml). Assay in triplicate.
Record Measurements: 1: , 2: , 3:
Mean of pool 2:  ((1,2,3)/3)
Pool 3:
(50%)
Combine 2 parts Pool 1 and 2 parts Pool 5 (e.g. 1.0 ml and 1.0 ml). Assay in triplicate.
Record Measurements: 1: , 2: , 3:
Mean of pool 3:  ((1,2,3)/3)
Pool 4:
(75%)
Combine 1 part Pool 1 and 3 parts Pool 5 (e.g. 0.5 ml and 1.5 ml). Assay in triplicate.
Record Measurements: 1: , 2: , 3:
Mean of pool 4:  ((1,2,3)/3)
Pool 5:
(100%)
No preparation necessary (use high sample near top of desired assay range). Assay in triplicate.
Record Measurements: 1: , 2: , 3:
Mean of pool 5: ((1,2,3)/3) 

Step Two: Prepare a Simple Plot (visual assessment of linearity)

A. Label the X axis for 0%, 25%, 50%, 75%, and 100% dilutions.

B. Label the Y axis for appropriate levels based on mean values or test assay range.

C. Plot coordinates. (0%, mean Pool 1), (25%, mean Mixture 2), (50%, mean Mixture 3), (75&, mean Mixture 4), (100%, mean Pool 5).

D. Draw best line through data points giving more weight to the first 3 coordinates.

E. Inspect plot for linearity and make a visual decision as to acceptable reportable range.

Cholesterol Example: Validation of Reportable Range Worksheet 1

Pool 1:
(0%)
No preparation necessary (use zero or very low sample). Assay in triplicate.
Record Measurements: 6, 6, 6
Calculate mean of pool 1: 6  
Pool 2:
(25%)
Combine 3 parts Pool 1 and 1 part Pool 5 (e.g. 1.5 ml and 0.5 ml). Assay in triplicate.
Record Measurements: 138, 138, 138
Calculate mean of pool 1: 138 
Pool 3:
(50%)
Combine 2 parts Pool 1 and 2 parts Pool 5 (e.g. 1.0 ml and 1.0 ml). Assay in triplicate.
Record Measurements: 278, 277, 279
Calculate mean of pool 1: 278
Pool 4:
(75%)
Combine 1 part Pool 1 and 3 parts Pool 5 (e.g. 0.5 ml and 1.5 ml). Assay in triplicate.
Record Measurements: 410, 411, 411
Calculate mean of pool 1: 411
Pool 5:
(100%)
No preparation necessary (use high sample near top of desired assay range). Assay in triplicate.
Record Measurements: 545, 546, 543
Calculate mean of pool 1: 545

When the above points are plotted, the following graph results:

The linearity of this example is very good.