CELL The cell is considered as structural and

functional unit of life

NUCLEUS MITOCHONDRIA It is largest cell organelle.

The nucleus of eukaryotic cell contains dense body known as NUCLEOLUS. It is rich in RNA

The ground material of the nucleus is referred as NUCLEOPLASM. It is rich in enzymes such as DNA polymerases and RNA polymerases.

They are regarded as power house of the cell

The outer membrane is smooth and inner membrane is folded to form CRISTEA which occur a larger surface area. The internal chamber of mitochondria

is referred as matrix or mitosol

ENDOPLASMIC RETICULUMA large portion of are is studded with ribosome's to

give granular appearance and is known as ROUGH ENDOPLASMIC RETICULUM.

RIBOSOMES ARE THE FACTORIES OF PROTEIN BIOSYNTHESIS.

The smooth endoplasmic reticulum doesn't contain ribosome's.It is involved in thesynthesis of lipids and metabolism of drugs,besides supplying calcium for cellular fractions.

GOLGI COMPLEX The cell contains a cluster of membrane

vesicles known as ‘Dictyososmes’. Which consists of Golgi apparatus involved in membrane synthesis particularly formation of intracellular organelles( peroxisomes, lysosomes)

PEROXISOMES LYSOSOMES

They are known as micro bodies. They are spherical or oval in shape

and contain the enzyme ‘Catalyze’ this protects the cell from toxic effects.

Lysosomes are spherical vesicles enveloped by single membrane. these are categorized as HYDROLASES

CELL COMPOSITIONChemical composition of a normal man ( weight 65 kg)

constituent Percent(%) Weight (kg)

Water

61.6 40

Proteins 17.0 11

Lipids 13.8 9

Carbohydrates

1.5 1

minerals

6.1 4Water is solvent of life and contributes to more than 60% of the weight. This is followed by protein( in muscle), and lipid( mostly in adipose tissue). The carbohydrate content is rather low which is in the form of glycogen.

ROLE OF CLINICAL BIOCHEMISTRY IN LABORATORY

1)Biochemistry plays an important role in diagnosing the diseases chemically in laboratory

2)The biological fluids employed in clinical Biochemistry laboratory include blood ,urine etc….3)Blood is frequently used For investigation in clinical Biochemistry laboratory.

COLLECTION OF BLOOD 1)Venous blood –for biological investigation2)Arterial blood –for blood gas determination

Precautions:-Use of sterile needles and syringes, cleaning of patients skin, blood collection in clean and dry test tubes are important precautions.

CHOICE OF BLOOD SPECIMENS Biological investigations can be

performed on 4 different types of blood specimens- whole blood, plasma , serum, red blood cells.

Plasma:-It is obtained by centrifuging the whole blood collected with an anticoagulant employed for fibrinogen , glucose.

Serum:-It is supernatant fluid that can be collected after centrifuging the clotted blood . The parameters estimated include proteins(albumin , globulins) , cholesterol, uric acid..

Red blood cells :-These are employed for determination of abnormal hemoglobins, glucose 6-phosphate.

Anti coagulants:-

Certain biochemical tests require unclotted blood . Anti coagulants are employed for collecting such specimens. Types of anticoagulants

HEPARIN(Inhibits conversion of prothrombin-thrombin). It does not cause change in blood composition

POTASSIUMOXALATE:- These compounds precipitate calcium and inhibits blood coagulation

AMMONIUM OXALATE AND SODIUM OXALATE:- A mixture of these compounds in the ratio 3:2 is used for blood collection to carry tests

EDTA:- It chelates with calcium and blocks coagulation. EDTA is employed to collect blood for hematological examinations.

TYPES OF LABORATORY TESTSBIOCHEMICALPROFILES METABOLIC WORK-UP TESTS

More useful information on the patients disease status can be analyzed rather than one e.g., liver function test( Serum, Bilirubin)

The identification of the endocrinological disorders come under this category

DYNAMIC FUNCTION TESTSThese test is designed to measure body’s response to external stimulus e.g., oral glucose test( to assess glucose homeostasis) and bromosulpthalein test( to assess liver function)

SCREENING TESTCommonly employed to identify the inborn errors of metabolism( Alkaptonuria (black urine disease), Tyrosinosis(tyrosinemia type-I)) and to check entry of toxic agents (pesticides, lead ,mercury) in to the body

Hemolysis 1)The rupture or lysis of RBC, releasing the cellular constituents interferes with laboratory investigations. Therefore utmost care should be taken to avoid hemolysis when plasma or serum are used for biological investigations 2)Use of dry syringes, needles , and containers allowing slow flow of blood in to syringe are among the important precautions to avoid hemolysis.

PRESERAVATION OF BLOOD SPECIMENS

Plasma or serum should be separated within 2 hrs after blood collection , and is advisable to analyse blood ,plasma or serum, immediately after the specimen collection.

Samples can be stored at 4 c ̊ until analyzed . For enzyme analysis , the samples are preserved at 20 c̊

separated within 2 hours

Collection of urine1) For biological investigations ,urine can be

collected as single specimen, usually collected in the morning, useful for qualitative tests for sugars, proteins , etc..

2) 24 hour urine collection are employed for quantitative estimation for hormones, proteins.

Quantitative investi-gationssugars,proteins

hormones

PRESERVATIVES FOR URNIE

HCL TOULENE

LIGHT PETROLEUM THYMOL

Cerebrospinal fluid

Collection of CSF:- It is collected from third and fifth lumbar vertebrae, under anesthesia conditions.

Normal range of CSF is 100-200 ml.

BIOCHEMICAL INVESTIGATION

chlorideproteinsglucose

Quality controlPRECISION

ACCURACY It refers to the reproducibility of

the result when the same sample analyzed for different occasion on the same person. The precision is good when blood glucose level is 78, 80, 82 mg/dl.

It means the closeness to the estimated result to the true value. E.g., if the blood urea level is 50 mg/dl, the laboratory reporting 45 mg/dl is more accurate than the reporting 35 mg/dl.

Specificity Sensitivity It refers to the

ability of the analytical method to specifically determine the particular parameter.

E.g., glucose can be specifically estimated by enzymatic glucose oxidase method

It deals with the ability of the particular method to detect the small amounts of the measured constituents.

ANALYSIS IN CLINICAL BIOCHEMISTRY LABORATORY AND REFERENCE VALUES

Clinical biochemistry is a laboratory service oriented absolutely essential for medical practice.

Biological investigations are used for diagnosis and prognosis of diabetes mellitus, jaundice ,gout etc…

FOR EXAMPLEThe concentration of glucose in the normal healthy individual is 75-110 mg/dl. If this exceeds above this concentration it leads to DIABETES MELLITUS , which is mainly characterized by HYPERGLYCEMIA that leads to several long complications.