Lakhasly

Introduction To Clinical Chemistry
Clinical chemistry: is the area of chemistry that is generally concerned with analysis of bodily fluids for diagnostic and therapeutic purposes. It is an applied form of biochemistry.
There are about 700 different kinds of tests in Clinical chemistry. This large array of tests can be categorized into sub-specialties of:

1. General or routine chemistry – commonly ordered blood chemistries (e.g., liver and kidney function tests).


2. Special chemistry - elaborate techniques such as electrophoresis.


3. Clinical endocrinology –study and diagnosis of hormones.


4. Toxicology –study of drugs of abuse and other chemicals.


5. Urinalysis – chemical analysis of urine for a wide array of diseases.
   Importance of Clinical chemistry
   • Diagnosis
   • Monitor progression of disease
   • Monitor effectiveness and complications of treatment
   • To prevent malpractice
   • To conduct research
   Specimen Collection and separation process
   There are four steps involved in obtaining a good quality specimen for testing:
   (1) preparation

• preparation of the patient: Provide the patient with appropriate collection instructions and information on fasting, diet, and medication.


• Preparing the Specimen: Proper identification of specimens is extremely important. All primary specimen containers must be labeled
  (2) collection of the specimen: This step includes the process of collecting specimens required for clinical tests from the patient, such as (blood, urine, saliva, cerebrospinal fluid) and placing them in appropriate and labeled containers.
  (3) processing the specimen: This step includes secondary processing that may be required to prepare samples for testing such as separation of whole blood into serum and plasma or sedimentation of urine contents.
  (4) storing and/or transporting the specimen: All specimen pots should be tightly sealed and transported using specimen bags. The request card should be placed in the pocket of the specimen bag, and the pot inside the sealed bag to ensure the safety of all staff.
  Samples types in clinical laboratory
  Any clinical laboratory expects the following samples:

1. 
   

   Urine sample.
   Can be used for general urine examination (GUE), urine culture and antibiotic sensitivity tests or for sugar test.

   
   


2. 
   

   saliva sample
   Saliva fluid is Produced in salivary glands, human saliva comprises 99.5% water, but also contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes. Medically, constituents of saliva can noninvasively provide important diagnostic information related to oral and systemic diseases.

   
   


3. 
   

   Cerebrospinal fluid sample
   Cerebrospinal fluid (CSF) is a clear, colorless, watery fluid that flows in and around your brain and spinal cord. Cerebrospinal fluid acts like a cushion that helps protect your brain and spinal cord from sudden impact or injury. The fluid also removes waste products from the brain and helps your central nervous system work properly.
   A CSF analysis is a group of tests that use a sample of your cerebrospinal fluid to help diagnose diseases of the brain and spinal cord and other conditions that affect the central nervous system.

   
   


4. 
   

   Blood sample.
   Can be classified in three types:
   A. Whole blood: Whole blood consists of red blood cells, white blood cells, and platelets suspended in a protective yellow liquid known as plasma It is collected by tubes contain anticoagulants e.g., EDTA and Heparin.
   
   B. plasma: It is a yellow liquid containing all the constituents of blood and coagulation materials except red and white blood cells and platelets. It is formed after the separation of the blood, which is mixed with anticoagulants such as heparin.
   C. Serum: Serum is the light-yellow liquid left after the blood coagulation process. It contains all blood components except for coagulation materials, red blood cells, white blood cells and platelets.

   
   

• Anticoagulants are compounds that prevent or delay clotting of blood by suppressing the synthesis or function of various clotting factors that are normally present in the blood such as heparin, EDTA, sodium acetate, sodium citrate, sodium fluoride.