Chapter- 4 : Reagents (solution) used in clinical laboratories

Dilution…..

• Diluting body fluids and calculating dilution.
• In the laboratory it is frequently necessary to dilute body fluids.
• Diluting body fluids
• Examples: To make 8ml of a 1 in 20 dilution of blood:
• Volume of blood required 8 = 0.4ml
• 20
• There fore to prepare 8 ml of a 1 in 20 dilution add 0.4ml of blood to 7.6ml of diluting fluid.
• Exercise
• If it desired to make 500ml of 0.2M solution of HCl from a 1.00 molar stock solution. How can we make it?
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4.4. Reagent solutions

• A reagent or reactant is a substance or compound consumed during a chemical reaction.
• A reagent is more specifically "a test substance that is added to a system in order to bring about a reaction or to see whether a reaction occurs".
• Such a reaction is used to confirm the presence of another substance.

Reagent …

• Reagent
• Any substance employed to produce a chemical reaction. In medical laboratory, this is used in conjunction with a given specimen to produce a measurable or noticeable change.
• The accuracy of tests depends to a great extent on the accuracy of the reagents used.

4.4.1. Types of reagent solutions

• 1. Stock reagent solution
• Is a concentrated reagent solution which is diluted to prepare a working solution.
• Has a longer shelf life and occupies less space in storage than the working solution.
• 2. Working –reagent solution
• Can be diluted from the stock solution or prepared directly from the reagent chemical following the recommended procedures.

Types of reagent …

• 3. Saturated solution
• Is a solution in which further solute can not be dissolved
• A saturated solution must have the deposits of the solute at the bottom of the reagent bottle.