Kuwait MOH Medical Laboratory Technician flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Anion gap formula

Anion gap = Na⁺ − (Cl⁻ + HCO₃⁻); normal 8–12 mmol/L. An elevated gap indicates unmeasured anions such as ketones, lactate, uremic toxins, or salicylate.

Friedewald LDL calculation

LDL = total cholesterol − HDL − (triglycerides/5), valid only when triglycerides are below 400 mg/dL. Above that, use a direct or Martin-Hopkins method.

Cardiac troponin

Troponin I or T is the preferred marker of myocardial necrosis because it is highly cardiac specific. CK-MB also rises after skeletal muscle injury and is less specific.

Hemolysis interference

Hemolysis falsely raises potassium, LDH, AST, and phosphate, and can falsely lower glucose and bilirubin. Report hemolyzed specimens with a comment or recollect.

MCV, MCH, MCHC

MCV = (Hct × 10)/RBC in fL; MCH = Hb/RBC × 10 in pg; MCHC = Hb/Hct × 100 in g/dL. MCHC above 36 g/dL suggests spherocytosis, lipemia, or cold agglutinin.

PT versus APTT

PT monitors the extrinsic pathway (factor VII) and warfarin therapy via INR. APTT monitors the intrinsic pathway and unfractionated heparin.

Corrected reticulocyte count

Corrected retic % = observed retic % × (patient Hct / normal Hct). It adjusts the raw count for the degree of anemia and reflects marrow response.

EDTA tube underfilling

Underfilled EDTA tubes concentrate the anticoagulant, shrinking red cells and falsely lowering MCV and hematocrit. Tubes must be filled to the marked line.

Coagulase-positive cocci

Gram-positive cocci in clusters that are catalase and coagulase positive are Staphylococcus aureus. Coagulase-negative staphylococci are common skin flora and contaminants.

MacConkey lactose reaction

Lactose fermenters such as E. coli form pink colonies on MacConkey agar. Non-fermenters such as Pseudomonas form colorless colonies and are usually oxidase positive.

Hepatitis B serology

HBsAg indicates current infection; anti-HBs indicates immunity; anti-HBc IgM indicates acute infection; HBeAg indicates high infectivity.

Malaria blood films

Giemsa-stained thick films are used for detection and thin films for species identification. Plasmodium falciparum shows multiple rings and banana-shaped gametocytes.

Sensitivity and specificity

Sensitivity = TP/(TP+FN); specificity = TN/(TN+FP). A highly sensitive test is best for ruling out disease; a highly specific test is best for confirming it.

ANA and anti-dsDNA

Antinuclear antibody by indirect immunofluorescence is a screening test. Anti-dsDNA and anti-Sm are highly specific for systemic lupus erythematosus.

Syphilis serology

Non-treponemal tests (RPR, VDRL) are used for screening and monitoring activity. Treponemal tests (TPPA, FTA-ABS, EIA) confirm the diagnosis.

Hypersensitivity types

Type I is IgE mediated; type II is antibody against cell-bound antigen; type III is immune complex deposition; type IV is T-cell mediated and delayed.

ABO compatibility

Group A has anti-B, group B has anti-A, group O has both, and group AB has neither. Group O is the universal red cell donor; AB is the universal plasma donor.

Direct antiglobulin test

The direct antiglobulin test detects antibody or complement bound to patient red cells, as in autoimmune hemolysis or a hemolytic transfusion reaction.

Indirect antiglobulin test

The indirect antiglobulin test detects antibody in serum by incubating serum with reagent red cells. It is used for antibody screening, identification, and crossmatching.

Acute hemolytic reaction

Usually caused by ABO incompatibility. Stop the transfusion, maintain saline access, notify the blood bank, and return the bag and post-transfusion samples.

Urine red cell casts

Red cell casts in urine indicate glomerulonephritis. White cell casts suggest pyelonephritis, and muddy brown casts suggest acute tubular necrosis.

Light's criteria

Pleural fluid is an exudate if the protein ratio exceeds 0.5, the LDH ratio exceeds 0.6, or LDH exceeds two-thirds of the upper normal serum value.

Synovial fluid WBC

Synovial WBC above 50,000/µL suggests septic arthritis; 2,000–50,000/µL suggests inflammatory arthritis; below 2,000/µL suggests non-inflammatory fluid.

Westgard 1-3s rule

A single QC value beyond mean ± 3SD is a rejection rule, indicating random or systematic error. The 1-2s rule is only a warning.

Westgard 2-2s rule

Two consecutive QC values beyond the same mean ± 2SD limit indicate systematic error and require rejection of the run and investigation.

Biosafety cabinet classes

Class I protects the operator only; Class II protects operator, product, and environment and is used for infectious aerosols; Class III is fully enclosed and gas-tight.

Coefficient of variation

CV = (SD/mean) × 100. It expresses precision as a percentage, allowing comparison of variability across analytes with different units and concentrations.

Ion-selective electrodes

Ion-selective electrodes measure sodium, potassium, chloride, and calcium by potentiometry. Indirect electrodes dilute the sample and are affected by hyperlipidemia and hyperproteinemia.

Real-time PCR Ct value

The cycle threshold is the PCR cycle at which fluorescence exceeds background. Ct is inversely proportional to the amount of target nucleic acid present.

PCR contamination control

Use a unidirectional workflow from reagent to sample to amplification, separate pre- and post-amplification areas, and include uracil-N-glycosylase to prevent carryover contamination.

MALDI-TOF identification

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry identifies bacteria by their protein mass fingerprint, giving rapid organism identification in microbiology.

Kuwait notifiable diseases

Diseases such as tuberculosis, measles, hepatitis, and HIV must be reported to the Kuwait Ministry of Health public health authority, per national regulations.

Patient confidentiality

Laboratory results are confidential and released only to authorized persons. Unauthorized disclosure is a disciplinary and legal violation under Kuwait health regulations.