Maharashtra HSC Medical Lab Technology (Vocational) common mistakes
Maharashtra HSC Medical Lab Technology (Vocational) · Understand the traps and how to avoid them.
At the spill station, pours undiluted household bleach onto a blood spill and wipes it up immediately, without preparing a fresh dilution or allowing contact time.
Memorises only that 'bleach disinfects' and does not link concentration, contact time and incompatibility with organic matter; also mixes bleach with detergent or acid without checking.
What to do instead
Prepare fresh 0.5% sodium hypochlorite (about 1:10 household bleach) for blood/body-fluid spills, apply from the edge inward, allow 10–30 minutes contact, absorb with disposable towels, and discard as biomedical waste; never mix hypochlorite with acids or ammonia.
For a chemical splash to the eye, searches for a neutralising agent or waits for transport before starting irrigation.
First-aid myths and panic lead candidates to think a chemical antidote is needed, when immediate dilution is the priority.
What to do instead
Start eye-wash or clean running water immediately, hold the lids open, irrigate for at least 15 minutes (20–30 minutes for alkali), remove contact lenses if present, then transport; do not use neutralisers.
Enters patient results after a single out-of-range control, or repeats only the control until it looks acceptable, without documenting rejection and corrective action.
Queue pressure and a misunderstanding that controls validate the whole analytical run, not just one repeat tube.
What to do instead
Stop the run, apply the Westgard rules (for example 1-3s or 2-2s rejection), repeat with fresh control material, troubleshoot reagent/calibrator/instrument, document the corrective action, and re-run all patient samples from that batch only after QC is in control.
States in viva that the pulmonary artery carries oxygenated blood and the pulmonary vein carries deoxygenated blood.
Names vessels by assumed oxygen content rather than by direction of flow, and memorises diagrams without tracing the pulmonary circuit.
What to do instead
Define arteries and veins by flow away from or toward the heart; trace right ventricle → pulmonary artery (deoxygenated) → lungs → pulmonary veins (oxygenated) → left atrium, and apply the same logic to the systemic circuit.
Collects electrolytes in an EDTA (lavender-top) tube, or uses a fluoride-oxalate tube for urea and creatinine and reports the result.
Tube-colour memorisation without understanding additive function; EDTA chelates calcium and contaminates the sample with potassium.
What to do instead
Use serum or heparinised plasma for electrolytes and renal function; reserve fluoride-oxalate for glucose and lactate; remember EDTA causes spuriously low calcium/magnesium and high potassium.
Assigns ABO group from forward (cell) grouping alone and ignores a reverse grouping discrepancy, or attempts reverse grouping on a 2-month-old infant.
Forward grouping looks simpler, reverse grouping is not understood as a check, and the age limitation of antibody production is forgotten.
What to do instead
Perform both cell and serum grouping; resolve any discrepancy (cold agglutinin, rouleaux, subgroup, Bombay phenotype) before issue; for infants under 4–6 months rely on forward grouping and maternal history because anti-A/anti-B are not yet reliably present.
Over-decolourises a Gram stain and reports Gram-positive cocci as Gram-negative, or accepts the autoclave pressure gauge alone as proof of sterilisation.
Rushing the decolourisation step and not using known control slides; equating pressure with temperature and exposure time.
What to do instead
Decolourise briefly with acetone-alcohol (about 5–10 seconds), check the colour of the runoff, and include known Staphylococcus aureus and Escherichia coli controls each batch; for sterilisation, use 121°C at 15 psi for 15–20 minutes and verify with chemical and biological indicators, not pressure alone.
Leaves a urine sample at room temperature for 2–3 hours before microscopy, then reports absent casts or red cells, or reads the dipstick after the stated reaction time.
Convenience and batch processing; casts and cells lyse, bacteria multiply and pH changes, while dipstick pads become invalid after their reading window.
What to do instead
Examine urine within 1 hour; if delayed, refrigerate at 2–8°C, warm to room temperature before dipstick, and note the delay; read each dipstick pad within its specified time and use fresh midstream clean-catch samples.
Places a biopsy in normal saline or in formalin at less than a 10:1 formalin-to-tissue ratio, or delays fixation until after transport.
Thinks any fluid preserves tissue and underestimates autolysis; the ratio and buffering requirements of formalin are not applied.
What to do instead
Immerse tissue immediately in 10% neutral buffered formalin at about 10 times the tissue volume, label the container, record fixation time, and avoid freezing or over-fixation; saline is not a fixative.
Reports a negative agglutination or serological test when the sample shows a prozone-like clear zone, or performs only one rapid test for HIV/HBsAg without confirmation.
Reads only the endpoint and does not dilute the sample; unfamiliar with prozone and with the need for a confirmatory strategy.
What to do instead
Dilute and retest the sample when prozone is suspected, include positive and negative controls in each run, and follow the recommended two- or three-test strategy and national guidelines before reporting a final serological result.