– First morning voiding (most concentrated)The morning sample is considered best as it has higher specific gravity and lower Ph and desirable for preservation of formed element.– Record collection time Use clean, dry and wide mouth container.– Analyzed within 1hours of collection– Free of debris or vaginal secretions
urinalyses are performed for several reasons:- General evaluation of health Diagnosis of metabolic or systemic diseases that affect kidney function Diagnosis of endocrine disorders. Twenty-four- hour urine studies are often ordered for these tests Diagnosis of diseases or disorders of the kidneys or urinary tract Monitoring of patients with diabetes Testing for pregnancy Screening for drug abuse
All the specimen for routine urinalysis should be examined while fresh(within one hr. of collection).when urine is kept for longer than one hr. before analysis, to avoid deterioration of chemical and cellular material and to prevent multiplication of bacteria, it should be stored at 2-8 c in a refrigerator.
The expected changes in the composition of urine stored at room temp. are as follow- Lysis of red blood cells by hypotonic urine. Decomposition of casts. Bacterial multiplication. Decrease in glucose level, due to bacterial growth Formation of ammonia from urea by the action of bacteria.
The recommended preservatives are as follow- Toluene Formalin Thymol Chloroform Commercial preservatives tablets. These release formaldehyde.
Types of Analysis − Physical Examination − Chemical Analysis (Urine Dipstick or by manual methods) − Microscopic Examination − Culture − Cytological Examination
It includes- Volume Color Appearance odour
Volume - for adults normal average daily volume of urine is about 1200-1500 ml. the normal range of 24 hr. urine may be from 600-2000 ml. Color - the color of normal urine may vary from pale yellow to dark amber. very pale or colorless urine can result from high fluid consumption, diuretic drugs, natural diuretic such as alcohol and coffee and also in clinical condition such as disbetes insipidus and diabetes mellitus.
Appearance - normal urine is usually clear. urine may appear cloudy or turbid from the presence of leukocytes and epithelial cells.this can be confirmed by microscopic examination. bacteria can also cause cloudiness to urine.fat and chyle give urine a milky colour. presence of RBCs may give urine turbid and smoky appearance. Odour - presence of ketone bodies gives urine a sweet or fruity smell.A contaminated urin with bacteria may give pungent smell due to the formation of ammonia
The routine urinalysis includes chemical testing for- Protein Glucose Ketone bodies Occult blood Bile pigments Bile salts urobilinogen
URINE is formed through a combination of four basic processes:- 1) Glomerular filtration, 2) Tubular reabsorption, 3) Tubular secretion, and 4) Water conservation. Blood is under high pressure in the glomerulus; thus, plasma (except for plasma proteins) moves into the glomerular capsule. This fluid is called filtrate. As the filtrate moves along the tubules, it is referred to as tubular fluid. Most of the water and many other molecules are reabsorbed into the blood, while some substances are secreted into the tubular fluid. Once the fluid moves into the collecting, duct it is called urine. While in the collecting duct, additional water is removed from the urine, concentrating the wastes.
General consideration - The microscopic examination is a valuable diagnostic tool for the detection and evaluation of renal and urinary tract disorders and other systemic diseases. Principle - The microscopic elements present in urine(in suspension)are collected in the form of deposit by centrifugation. A small drop of the sediment is examined by making a coverslip preparation under microscope.
Requirements - Centrifuge tube or test tube(10*15mm) Glass slide Cover slips Pasteur pipettes Centrifuge Microscope Specimen - Freshly voided urine is required
Procedure - Mix the urine and pour into a centrifuge tube(or small test tube)until it is ¾ fill(5 ml) Centrifuge with another balanced test tube for 5 min at 2500 rpm. Pour off the supernatant quickly and complete into another test tube.This can be used for protein determination Resuspend the deposits by shaking the tube. Place one drop of the deposits on a glass slide. Cover it with coverslip and mark it with identification number. Observe it first under low power objective in partially closing the diaphragm and then adjusting the condenser downward until satisfactory contrast is obtained.Note the content of various fields. Switch to high dry objective and observe at least 10 to 15 different fields
Starch crystals Fibers Oil droplets Hair Air bubbles
In fresh urine these cells have a normal, pale or yellow appearance. They appear smooth, biconcave disks about 7 um in diameter and 2um thick. They do not contain nuclei. In hypotonic urine the red cells swell up and lyse. In hypertonic urine the red cells crenate.
Originate from any site in the genitourinary tract from the proximal convoluted tubule to the urethra or from vagina. Normally few cells(3-5) per h.p.f from these sites can be found in the urin. Three types of epithelial cells may be recognised-Tubular Transitional Squamous
These are slightly larger then leucocytes and contain large round nucleus. They may be cuboidal, flat or columnar
Urinary castes are formed in the lumen of the tubule of the kidney. The renal tubules secrete a mucoprotein called Tamm- Horsfall protein which is believed to form the basis matrix of all casts. Casts dissolve in alkaline urine Castes have nearly parallel sides and rounded or blunted ends. These are of followings types-1. Granular2. Hylaine3. Red cell casts4. White cell casts5. Epithelial cell casts6. Waxy casts7. Fatty casts
These always indicate significant renal disease.The casts are present due to the degeneration of cellular casts or due to direct aggregation of serum protein in a Tamm-horsfall mucoprotein matrix.
They are colorless, homogeneous,Transparent and with rounded ends. These casts can be seen in increased number even in the mildest kind of renal disease. A few hyaline casts may be present in normal urine.
The cast may contain only a few RBC’s in protein matrix or may be many cells packed close together with no visible matrix. Presence of red cell is always pathogenic. They are usually diagnostic of glomerular disease being found in acute glomerulonephritis and also in renal infarction.
The majority of white cells that appear in casts are polymorphonuclear neutrophils. The cells may be few or many, tightly packed together. These casts may be present in renal in renal infection and in glomerular disease.
The epithelial cells may be arranged hephazardly and vary in size and shape.These casts are rarely seen in urine . Presence of these casts indicate tubular degeneration and necrosis. Present in severe chronic renal disease.
Crystals present in acidic urine……. Uric acid crystals -These can occur in most charactristic diamond rhombic or rosette form.These are usually stained with urinary pigments as yellow or red brown.These are soluble in sodium hydroxide and insoluble in hcl. Pathological conditions - Gout, chronic nephritis, acute febrile condition.
These are colorless and envelop shaped. They also appear as oval, sphere or biconcave disks which have a dumb bell shape(when viewed from side). These are found in acid or neutral urine.These can be present in urine after the ingestion of tomatoes, oranges and vitamin c. Pathological condition-They can be present in diabetes mellitus, liver disease and chronic liver disease.
Calcium oxalate crystals in urineCalcium oxalate crystals are usually found inacid urine. They commonly appear octahedral.
These are urate salts of sodium, potassium, megnesium and calcium. Usual form is non crystalline and amorphous and appearance is yellow- red granular. These are soluble in alkali at 60 c. They have no clinical significance.
Amorphous urates in urineAmorphous urates appear as fine pink orbrownish-tan granules. They are salts of uricacid and are normally found in acid or neutralurine.
These may be present as amorphous or as crystals. These crystals are colorless or yellowish needles occurring in clusters. They are soluble at 60 c. They have no clinical significance.
These are colorless, hexagonal plates with equal or unequal sides. These are soluble in hydrochloric acid and ammonia. Pathological condition-They occur in patients with either congenital cystinosis or congenital cystinuria.They can form calculi.
Cystine crystals in urineCystine, an amino acid, is an abnormal findingin urine. Rarely seen, these crystals are foundin acid urine and are seen as thin, colorless,hexagonal plates.
These appear in the form of fine, refractile needles, occurring in clusters. These are soluble in ammonium hydroxide. Pathological conditions-severe liver disease and tyrosinosis.
Tyrosine crystals in urineTyrosine crystals are not normally found in urine. They are products of proteinmetabolism and appear in urine of people with tissue degeneration or necrosis (acuteliver disease, severe leukemia, typhoid fever, and smallpox). They are present onlywhen urine is acid. They are colorless to yellowish brown, needle shaped crystals andhave a fine silky appearance. The needles may be single or arranged in sheaves orrosettes. Tyrosine crystals usually appear in urinary sediment together with leucinecrystals
These crystals are oily, highly refractile spheroids . They have yellow or brown color. These crystals are soluble in hot alcohol and acetic acid. Pathological conditions-severe hepatitis, acute yellow atrophy.
Leucine crystals in urineLeucine crystals are not normally found in urine They appear in urine inassociation with tyrosine and are manifestations of the same clinical conditions.When found, leucine crystals are in acid urine in the form of spheroids withconcentric striations. They are dense, highly refractive and appear as yellowishbrown bodies.
These crystals are large flat and in the form of transparent plates with notched corners. These are soluble in either chloroform and hot alcohol. Pathological conditions- Nephritis, Nephrotic conditions, excessive tissue breakdown.
Most of the sulfa drugs precipitate out as sheaves of needles. They may be clear or brown in color and usually appear with eccentric binding. These drugs are soluble in acetone.
Sulfa crystals in urineSulfonamide crystals form primarily in acid urine. The shape and color of thesecrystals are extremely variable, depending on the particular sulfonamide beingadministered to the patient. The most common forms encountered include rosettes, fanshapes and those resembling shocks of wheat. Sulfa crystals have pathologicsignificance, since they tend to form renal calculi that may damage renal tubules.
Crystals found in alkaline urine. The crystals are colorless prisms with three to six sides and frequently with oblique end. Soluble in acetic acid. Frequently found in normal urine. Pathological conditions-chronic cystitis, chronic pyelitis, enlarged prostate.
Triple phosphate crystals in urineTriple phosphate crystals, resemble prisms or"coffin lids". They are found normally inalkaline or neutral urine. They are colorless.
These are present in amorphous, granular form. They have no clinical significance.
Amorphous phosphates in urineAmorphous phosphates appear in neutral to alkaline urine as fine, colorlessor slightly brown granules. White precipitate is observed on centrifugation.
These appear as small, colorless and in the form of spherical, dumbbell shape or as granular type. They have no clinical significance.
Calcium carbonate crystals in urineCalcium carbonate crystals are small andcolorless and appear in alkaline urine asgranules or as small dumbbells. Bacteria arealso present in this field.
These are long, thin and colorless.The appearance is like prisms with one pointed end, arranged as rosettes or stars. Soluble in dilute acetic acid. May be present in normal urine and have no clinical significance.
Calcium phosphate crystals in urineCalcium phosphate crystals assume variousforms including the rosette and pointed fingerforms. They appear most often in alkalineurine.
These are yellow brown or spherical bodies with or without long, irregular spicules. Presence is abnormal if they are found in fresh urine.
Ammonium biurate crystals in urineAmmonium urate crystals are easilydistinguished by their golden brown color and"thorn apple" shape. They are the only uratecrystals that appear in alkaline urine.
Starch crystals - These are found in urine as round or oval and highly refractile crystals. Fibres - they may come from clothing, toilet paper or may be lint from the air. Oil droplets - these are present as the result of contamination from lubricants.they are spherical and vary in size. Hair Air bubbles parasites
A R TStarch crystals I Oil droplets F A C T Air bubbles S Hair