Blood Tests

Taking a blood sample

• Tie a tourniquet around the arm to make the vein stand out
• Clean the area with an alcohol wipe 
• Push a sterile needle into the vein
• Pull back the plungler, blood is sucked into the syringe 
• Remove the needle when necessary amount of blood is taken 
• Hold a ball of cotton on the wound 
• Apply a dressing 

Making and Staining a blood film 

• Place a small drop of blood near the end of a clean slide 
• Use another slide at a 30 degree angle to spread the blood, making a smear 
• Allow the slide to air dry 
• Fix the slide with alcohol (methanol), which perserves the cells 
• Stain the slide with leishmanns stain 
• Wash the stain off with water 

Key Definition

A differential stain makes some structures appear darker or a different…