Maharashtra HSC Medical Lab Technology (Vocational) key terms

Work practice in which every sample of blood, body fluid, secretion or tissue is handled as if it carries HIV, hepatitis B and other blood-borne infections. It requires gloves, lab coat, eye protection, safe sharps disposal and hand washing after each procedure.

Nationally prescribed scheme for separating laboratory waste into colour-coded bins: yellow for infectious and anatomical waste, red for contaminated recyclable plastic, white translucent for sharps, and blue for glassware and metallic items.

Puncture-resistant, leak-proof, lidded box used to discard used needles, blades, lancets and broken glass at the point of use, so that laboratory and housekeeping staff are not injured or inoculated.

Emergency first aid that maintains circulation and breathing in a person who is unresponsive and not breathing normally, using chest compressions at 100 to 120 per minute, with rescue breaths or hands-only technique, until help arrives.

Rapid, life-threatening whole-body allergic reaction with airway swelling, wheeze, falling blood pressure and skin rash. First-line treatment is intramuscular adrenaline into the outer thigh, with oxygen and urgent hospital transfer.

Voluntary agreement of a patient or guardian to a test, procedure or use of their sample, given after the purpose, risks, alternatives and confidentiality are explained in language the person understands.

Daily testing of control samples of known value alongside patient samples to check that a method is performing within preset limits; results are plotted on a chart and the run is rejected when rules are broken.

Scheme in which an outside agency sends unknown samples to many laboratories; each laboratory's results are compared with the peer group or reference value to reveal bias that internal quality control cannot detect.

The body's ability to keep internal conditions such as temperature, pH, blood glucose and electrolyte levels within narrow limits despite outside changes, mainly through negative feedback loops involving nerves and hormones.

Immediate protective response to injury or infection, marked by redness, heat, swelling, pain and loss of function, with vasodilatation, increased capillary permeability and migration of neutrophils into the affected tissue.

Uncontrolled death of cells or tissue in the living body after injury, ischaemia, infection or toxin exposure, followed by inflammation; common forms include coagulative, liquefactive and caseous necrosis.

The clear fluid left after whole blood has clotted and the clot has been separated by centrifugation. It lacks clotting factors and fibrinogen but is otherwise similar to plasma, and is preferred for many biochemistry tests.

The fluid part of unclotted blood, obtained by centrifuging blood collected into an anticoagulant such as EDTA, citrate or heparin. Unlike serum, it still contains fibrinogen and the clotting factors.

Blood glucose measured after at least eight hours without food, usually an overnight fast. It is the basic test for diagnosing and monitoring diabetes, with 126 mg/dL or more on two occasions indicating diabetes.

Estimated glomerular filtration rate calculated from a timed urine volume, its creatinine concentration and the matching serum creatinine. It shows how well the kidneys clear a waste product and helps detect early renal impairment.

The iron-containing red pigment of erythrocytes that carries oxygen from lungs to tissues. Measured in g/dL, it is the main index of anaemia and is estimated by colorimetric, cyanmethaemoglobin or automated methods.

Percentage of the blood volume occupied by red cells after centrifugation of an anticoagulated sample in a capillary or Wintrobe tube. It correlates with haemoglobin and reflects anaemia or polycythaemia.

Average volume of a single red cell, derived from haematocrit divided by red cell count. It classifies anaemia as microcytic, normocytic or macrocytic and is a core red cell index in automated analysers.

Rate at which red cells settle in a vertical column of anticoagulated blood in one hour, usually by the Westergren method. It is a nonspecific marker of inflammation and also rises in anaemia and pregnancy.

Testing that finally checks compatibility between a patient's serum and donor red cells before transfusion, performed after ABO and Rh grouping to prevent haemolytic transfusion reactions.

Purple-top anticoagulant that binds calcium and prevents clotting. It is the salt of choice for full blood counts and blood grouping because it preserves cell shape and staining, but is unsuitable for calcium and some enzyme assays.

Process that destroys all micro-organisms including bacterial spores, for example moist heat in an autoclave at 121 degrees Celsius for 15 minutes, or dry heat, ethylene oxide and filtration for heat-sensitive items.

Differential stain in which crystal violet and iodine are applied, then decolourised with alcohol; Gram-positive organisms retain the purple dye while Gram-negative organisms take the pink counterstain safranin. It guides initial identification and treatment.

Nutrient preparation that supplies water, nitrogen, carbon, salts and growth factors for micro-organisms; it may be solid with agar, liquid, selective or enriched, and is used to isolate colonies from a specimen.

Standardised method for antibiotic susceptibility: a lawn of bacteria is spread on Mueller-Hinton agar, antibiotic discs are applied, and zone diameters are compared with standard charts to report sensitive, intermediate or resistant.

Pair of smears used in malaria diagnosis. The thick film concentrates parasites for detection, while the thin film, fixed in methanol, allows species and stage to be identified from the appearance of infected red cells.

Plastic strip carrying reagent pads that change colour on contact with urine, giving rapid semi-quantitative results for pH, protein, glucose, ketones, blood, bilirubin, nitrite and leucocyte esterase; positive results need microscopic confirmation.

Cylindrical mould of the renal tubule formed from protein and cells within the tubule lumen and seen on urine microscopy. Hyaline casts are benign, while red cell or granular casts suggest glomerular or tubular disease.

Test for hidden blood in stool, using guaiac-based or immunochemical methods, used in screening for colorectal cancer and in investigating anaemia; dietary and drug interference must be controlled.

Immersion of tissue in buffered 10 percent formalin, which cross-links proteins and preserves structure for paraffin processing while preventing autolysis and bacterial growth; it is the usual fixative in histopathology.

Procedure in which cells are drawn through a thin needle from a palpable lump and smeared on a slide for microscopic study, giving a quick diagnosis without surgery.

Instrument that cuts uniformly thin sections, usually three to five micrometres, from paraffin-embedded tissue so that they can be mounted on slides, stained and examined under the microscope.

Enzyme-linked immunosorbent assay: antigen or antibody is bound to a solid phase and detected with an enzyme conjugate that converts a substrate to a coloured product measured in a reader; used for HIV, hepatitis and hormone tests.

Tube agglutination test that detects antibodies against Salmonella O and H antigens in serum, used as an aid in diagnosing enteric fever; paired samples showing a rising titre are more meaningful.

Instrument that measures the intensity of colour in a solution by passing a chosen wavelength through it and comparing absorption with a blank, applying the Beer-Lambert law to calculate concentration.

Machine that spins tubes at controlled speed to separate components by density, for example cells from plasma or serum from clot; tubes must be balanced and the rotor checked for cracks before use.

Pear-shaped glass vessel with a long neck and a single calibration mark, used to prepare a solution of exact volume at a stated temperature; the meniscus is read at eye level.

High-purity chemical grade suitable for analytical work, with maximum limits of impurities stated on the label; it is used for preparing standards and reagents in the clinical laboratory.