The indole (modified Kovacs ' reagent) is used to assess the ability of certain bacteria to produce indole by the deamination of tryptophan. Indole reacts with aldehyde in the Kovac ' s reagent to produce a red color. An alcoholic layer holds the red color as a ring at the top of the tube used for the idole test.

If a bacteria produces the enzyme tryptophanase to break down the amino acid tryptophan, which of the following tests will be positive with Kovac ' s reagent?

Caffeine benzoate solution is used to split the unconjugated bilirubin protein complex releasing the bilirubin so that it can react with diazotised sulphanilic acid. The tartrate buffer creates an alkaline solution and converts the red acid bilirubin to a green coloured compound which can be measured spectrophotometrically.

Which substance is used in the Jendrassik-Grof method to accelerate the reaction of unconjugated bilirubin with the diazo reagent?

In healthy individuals, procalcitonin is only synthesized by the thyroid C cells. In bacterial infections, PCT is synthesized in various extrathyroidal neuroendocrine tissues.

In healthy individuals, procalcitonin is synthesized by which cells in the body?

Assuming an alpha hemolytic reaction (not well seen in the image), viridans streptococcus and S. pneumoniae are the two possible responses. However, these colonies are far too mucoid for viridans streptococci; therefore, S. pneumoniae is the most likely choice. Also, the colonies are much too large and the hemolytic reaction is wrong for S. pyogenes or S. agalactiae.

A patient was admitted to the hospital recently with an obvious infection. A sputum specimen was submitted and the microbiologist inoculated it to sheep blood agar. Based on the colony morphology and the alpha hemolysis seen in the image to the right, the most likely identification is:

In sickle cell anemia, rapid hemoglobin turnover may be present. HbA1C and other glycated hemoglobin assays are not valid in rapid hemoglobin turnover and in abnormal hemoglobin conditions. Fructosamine measurements can be used because of shorter half life of albumin.

HbA1C measurements are NOT ordinarily used to monitor long-term diabetic control in a diabetic with sickle cell anemia.

Hb S migrates with D in alkaline and alone in acid electrophoresis.

The gel electrophoresis pattern for hemoglobin S shows which of the following migration patterns?

Troponin is a very specific biomarker that is released during cardiac injury or stress. CK is found not only in cardiac tissue, but also in muscle and brain tissue. LD levels can be elevated in cardiac events, tissue breakdown, and hemolysis. Myoglobin is elevated when muscle tissue is damaged and is not specific for the heart muscle.

Chemistry

Which one of the following is the MOST specific biochemical marker of myocardial infarction?

The correct set of patient data would be: Hgb A = 60%, Hgb S = 38%, Hgb A2 = 2%, Hgb F = 0%

Patients with sickle cell trait commonly have Hgb A values between 40 and 60%, Hgb S values between 20 and 40% and Hgb A2 values between 2 and 3%.

A known sickle cell trait patient has a hemoglobin electrophoresis test performed. Which of the following hemoglobin percentage sets would most closely match this patient ' s diagnostic state?

The Clinical Laboratory and Standards Institure (CLSI) recommends that all patient specimens are delivered to the laboratory no more than 2 hours after collection to reduce pre-examination variables caused by cellular action and the effects of prolonged exposure of specimens to room temperatures, such as:

Question options:

Flow cytometry employs a combination of fluorescent antibody tagging of cells and analysis with laser light scatter.

What principle(s) of flow cytometry are employed when performing immunophenotyping:

Coumarin derivatives inhibit the vitamin K dependent Factors (II, VII, X) which can be measured with the PT and monitored frequently with the INR assay.

Hematology

Warfarin-based (coumarin derivative) oral anti-coagulant therapy is commonly monitored with :

Provide the equivalent measurement for 1000 milligrams.

Question options:

The conidia of Exophiala species are produced within phialides that extrude the conidia in tight, ball-like clusters.

The large, drum stick-shaped muriform macroconidia of Alternaria species are arranged in short chains; the small, elliptical conidia of Cladosporium species are arranged in both long and short, branching chains.

Which of the following dematiaceous fungal species produce conidia in clusters?

The characteristic that distinguishes vancomycin-resistant Enterococcus faecium and Enterococcus faecalis from other Enterococcus species is their lack of motility.

Enterococci are all catalase-negative. Growth on bile esculin agar and in 6.5% salt broth are two characteristics that have commonly been used to identify Enterococcus to the genus level. A positive esculin in combination with a positive PYR reaction is another approach to presumptive identification.

Which one of these characteristics distinguishes vancomycin-resistant Enterococcus faecium and Enterococcus faecalis from other Enterococcus species?

Anything that can cause significant turbidity in a blood sample, such as high leukocyte count or lipemia can potentially interfere with the accuracy of a spectrophotometric hemoglobin assay.

Hematology

Which of the following may interfere with the accurate measurement of hemoglobin: