CSMLS MLT Exam flashcards

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

Anion gap formula

Anion gap equals sodium minus the sum of chloride and bicarbonate, typically 8 to 16 mmol/L. An elevated gap indicates accumulation of unmeasured anions such as ketones, lactate, or toxins.

Corrected reticulocyte count

Multiply the reticulocyte percentage by the patient hematocrit divided by a normal hematocrit. This adjusts for anemia severity and indicates whether marrow response is adequate.

Coagulase test

A test that detects coagulase enzyme in gram-positive cocci in clusters. A positive result identifies Staphylococcus aureus, while coagulase-negative staphylococci are usually skin flora.

Indirect antiglobulin test

Detects unexpected antibodies in patient serum that bind reagent red cells in vitro. It is used for antibody screening and crossmatching before transfusion.

Hematoxylin and eosin stain

Routine histology stain in which hematoxylin colors nuclei blue-purple and eosin colors cytoplasm and collagen pink. It provides general tissue architecture and cellular detail.

IgM versus IgG

IgM is a pentamer produced early in infection and does not cross the placenta. IgG is a monomer produced later, crosses the placenta, and dominates the secondary response.

Westgard 1-3s rule

A QC rejection rule triggered when a single control value falls more than three standard deviations from the mean. It indicates random error and requires investigation before reporting.

Order of draw

Sequence for venipuncture: blood culture, sodium citrate, serum, heparin, EDTA, then fluoride-oxalate tubes. Following it prevents additive cross-contamination between tubes.

Coefficient of variation

The standard deviation divided by the mean, multiplied by 100, expressed as a percentage. It describes assay precision and allows comparison between methods or analytes.

Light criteria

Rules classifying pleural fluid as exudate when pleural protein or lactate dehydrogenase ratios to serum exceed thresholds. Exudates suggest inflammation, infection, or malignancy.

Troponin interpretation

Cardiac troponin I or T rises with myocardial injury. A rise and fall pattern with clinical evidence of ischemia defines acute myocardial infarction rather than chronic injury.

Iron deficiency profile

Microcytic anemia with low ferritin, low serum iron, and high total iron-binding capacity. Ferritin is the most sensitive indicator of depleted iron stores.

MacConkey agar

Selective and differential medium for gram-negative rods. Lactose fermenters form pink colonies, while non-fermenters remain colorless, aiding organism identification.

Direct antiglobulin test

Detects antibody or complement bound to red cells in vivo using anti-human globulin reagent. A positive result supports immune hemolysis or a hemolytic transfusion reaction.

Periodic acid-Schiff stain

Stains glycogen and mucin magenta. Diastase digestion removes glycogen but not mucin, allowing distinction between glycogen storage and mucinous material.

Antinuclear antibody test

Screening immunofluorescence test for antibodies against nuclear antigens. It is sensitive for systemic lupus erythematosus but not specific, so clinical correlation is required.

Levey-Jennings chart

Graph of QC results over time with mean and standard deviation limits. Systematic error shifts the mean, while random error increases scatter around it.

Citrate tube fill

Sodium citrate coagulation tubes must be filled to the marked volume. Underfilling raises the anticoagulant-to-blood ratio and falsely prolongs clotting times.

Beer-Lambert law

Absorbance is proportional to concentration and light path length. Deviations occur at high absorbance, with stray light, or when the analyte is not homogeneous.

Urine nitrite test

A positive nitrite result suggests nitrate-reducing bacteria, most commonly Enterobacterales. A negative result does not exclude infection because some organisms do not reduce nitrate.

Calculated osmolality

Calculated osmolality equals twice sodium plus glucose plus urea, all in mmol/L. A measured-to-calculated gap above 10 suggests an unmeasured osmole.

D-dimer use

D-dimer is highly sensitive but poorly specific for venous thromboembolism. A negative result in a low-probability patient helps exclude the diagnosis.

Minimum inhibitory concentration

The lowest antimicrobial concentration that inhibits visible bacterial growth. It is determined by broth microdilution or gradient strips and guides antimicrobial selection.

Rh immune globulin

Anti-D immunoglobulin given to D-negative mothers to prevent anti-D alloimmunization. Dose is guided by the volume of fetomaternal hemorrhage.

Masson trichrome stain

Stains collagen blue-green and muscle red, highlighting fibrosis. It is useful for assessing liver fibrosis and other connective tissue changes.

Rheumatoid factor

An antibody directed against the Fc portion of IgG. It is sensitive but not specific for rheumatoid arthritis and can occur in other inflammatory or infectious conditions.

Delta check

A rule comparing a current result with the patient's previous result. An unexpected difference triggers review before release to detect error or specimen mix-up.

Hemolysis effect

Red cell rupture releases potassium, lactate dehydrogenase, and aspartate aminotransferase. It falsely elevates these analytes and interferes with many spectrophotometric assays.

Ion-selective electrode

An electrode that measures electrolyte activity in solution. Indirect methods dilute the sample and can be affected by hyperproteinemia or hyperlipidemia.

Red cell cast

A cast containing red blood cells that indicates glomerular bleeding, as in glomerulonephritis. Dysmorphic red cells in urine support the same interpretation.

Febrile nonhemolytic reaction

The most common transfusion reaction, presenting with fever and chills without hemolysis. It is usually managed by stopping the transfusion and evaluating for other causes.