Construct a standard curve (it will be a straight line) by taking the mean of the duplicates for each standard.

You are supplied with a set of data for each of the three colorimetric assays and a protein electrophoresis.  Guidelines on the interpretation are provided below.

For each colorimetric assay:

1. Construct a standard curve (it will be a straight line) by taking the mean of the duplicates for each standard.
2. Using this, determine the values of analyte for the patient sample and the quality control, again using the mean of the duplicate absorbances.  (The sample blanks will need to be deducted from absorbances for total and direct for the bilirubin assay.)
3. Compare the quality control to its expected value to ascertain whether the assay is valid.  It should be within 10%.
4. If the assay is valid, compare the results for the patient to the reference range in the practical booklet.
5. Study the schematic electrophoretic pattern shown in Figure 1 and consider how it could be interpreted.
6. Decide whether the patient results are normal or abnormal.
7. Using the notes on the Patient Request Form, also provided, consider the meaning of the data.

For the electrophoresis compare the patient to the control serum and comment on the findings.  Also try to link the significance of these data with the other assays.

Write the results and a summary of the findings in your logbook.

Patient Request Form

Surname  Manning		Forename Christopher
DOB 16/02/1951	UR X881952	NHS
Address 49 Everest Close
Letchworth
Drs Name K A Anderson
Surgery Address  Princes Avenue Group Practice, 59 Princes Avenue, Letchworth
Clinical History Weight loss EtOH?
Tests requested LFTs, γGT

Total Protein by Biuret

Sample	Concentration (g/L)	Absorbance 1	Absorbance 2
Standard blank	0.00	0.000	0.002
Standard 1	10.00	0.070	0.064
Standard 2	20.00	0.172	0.163
Standard 3	40.00	0.226	0.234
Standard 4	60.00	0.385	0.387
Standard 5	80.00	0.451	0.437
Standard 6	100.00	0.550	0.542
Patient		0.234	0.221
Quality control		0.275	0.263

 

 

Albumin by Bromocresol green

 

Sample	Concentration (g/L)	Absorbance 1	Absorbance 2
Standard blank	0.00	0.000	0.000
Standard 1	5.0	0.116	0.115
Standard 2	10.0	0.251	0.248
Standard 3	20.0	0.374	0.372
Standard 4	30.0	0.512	0.520
Standard 5	40.0	0.662	0.651
Standard 6	50.0	0.810	0.823
Standard 7	60.0	0.904	0.893
Standard 8	70.0	1.088	1.042
Patient		0.412	0.426
Quality control		0.521	0.518

Bilirubin by Jendrassik & Grof method

Sample	Concentration (µM)	Absorbance 1	Absorbance 2
Standard blank	0.000	0.000	0.001
Standard 1	10.0	0.030	0.032
Standard 2	20.0	0.055	0.049
Standard 3	35.0	0.092	0.097
Standard 4	55.0	0.158	0.162
Standard 5	75.0	0.202	0.200
Standard 6	90.0	0.266	0.252
Patient blank		0.006	0.005
Patient direct		0.015	0.016
Patient total		0.053	0.049
QC blank		0.002	0.001
QC direct		0.068	0.061
QC total		0.211	0.198

Figure 1:  schematic diagram of serum protein electrophoretic pattern for patient and quality control

Details of Quality Control Serum	Expected values for Quality Control Serum
Lot no: 428UE	Total protein:  47.5 g/L
Expiry Date: 2021-02	Albumin:  31.1 g/L
	Direct bilirubin:  37.7 μmol/L
	Total bilirubin:  91.2 μmol/L

Details on sample label:                 Patient name: Manning, Christopher

Date of birth: 16/02/1951