**2.11.1 Princile**

52 Chronic Kidney Disease

The Cresolphtalein- Complexone method (CPC) was used for the determination of total serum calcium. This is a standard Colorimetric method. This like most calcium assays measures the total serum calcium although it is only the free calcium which constitutes 50-

CPC forms a violet colored complex with calcium. The absorbance of the colour produced was measured in a colorimeter using a Spectrophotometer at 575nM wavelength measured in a colorimeter using a spectrophotometer at 575nM wave length. Interference from magnesium was reduced by including 8-hydroxquinoline in the working CPC reagent. The Ethanediol in the reagent suppresses the ionization of the 0- Cresolphtalein and helps to give a clear solution. A correction was made when the patient's serum albumin level was

> <sup>2</sup> albumin g /l Ca <sup>40</sup> 40

**2.10 Measurement of total serum calcium** 

65% of total calcium that is biologically active.

1. Two sets of four tubes were labeled as follows: B-reagent blank, standard (2mmol/l)

2. 5mls of CPC reagent was added into each tube using a pipette

The contents of each tube were mixed for several seconds.

Serum calcium values of 8.5 – 10.5mg/dl was taken as normal.

3. The following were added into each set of tubes using a pipette as follows:

4. Using clean Cuvettes, the absorbance of the solution were read in a colorimeter using a spectrophotometer set at 575nM. The instrument was zero with a blank solution in tube

5. The concentration of Ca2+ in the patients sample was calculated with the following

This was done using the kind and king method (1954). This is a standard colorimetric

Ca2+ (mmo1/L) = AT <sup>2</sup>

AS

C - Control; p - patient.

AT= Absorbance of test or control AS= Absorbance of standard

**2.11 Measurement of serum alkaline phosphatase** 

B. - 0.05mls distilled water S - 0.05mls standard (2mmol/1) C- 0.05mls Control serum p - 0.05mls patient serum

**2.10.1 Principle** 

below 40g/l using this formula:

Corrected serum albumin =

**2.10.2 Method** 

B.

method.

formula:

4- amino antipyrine gives a red purple colour with compounds containing a phenolic group in the presence of alkaline oxidizing agents.
