Practice BOC
After experiencing extreme jaundice, abdominal pain, and vomiting from extensive hepatocellular damage, a patient's hepatic function panel is analyzed in the laboratory. The result of the ALT is too high for the instrument to read. Since the instrument does not perform automatic dilutions for ALT, the laboratorian performs a dilution using 100 microliters of patient sample to 400 microliters of diluent. The result now reads 369 U/L. How should the laboratorian report this patient's ALT result?
1,845 U/L
Whole blood or red blood cell units will be shipped from the American Red Cross to the transfusion facility. At what temperature should the units be kept during transportation?
1-10 °C
The laboratory workplace includes many hours of computer use. The suggested time for a break after 30 minutes of computer use is
1-2 minute break
Which of the following is a clinical finding of Myelodysplastic Syndrome with Excess Blasts subtype 2 (MDS-EB-2)?
10 to 19% blasts in the Bone Marrow
What percentage solution of sodium hypochlorite (bleach) is recommended as a routine laboratory disinfectant?
10%
A technologist is evaluating the red blood cell morphology on a peripheral blood smear. The image on the right is a representative field from the smear. The technologist has recorded the red cell morphology as macrocytic. Which MCV value would confirm this observation?
110fL
Which of the following donors could be accepted for blood donation?
24-year-old man who had a tooth extraction two months ago
Ammonia is BEST characterized as being:
A waste product of amino acid and protein metabolism
The plant lectin obtained from the Dolichos biflorus plant will agglutinate which of the following?
A1 cells
The lectin Dolichus biflorus agglutinates which types of cells?
A1B
When processing umbilical cord blood samples for hematopoietic progenitor cells (HPC), what tests are performed on both the mother's blood and cord blood?
ABO & Rh
The image is of an organism that measures 12 µm and is found in stool. What is the identification of this organism?
Blastocystis hominis
Urine crystals of radiographic contrast media will appear similar to which of the following?
Cholesterol crystals
Based on the reactions observed in the tubes shown in the photograph (including open and closed OF dextrose and a positive nitrate reaction only after the addition of zinc dust, as shown in the right tube of the pair labeled "Nit"), the most likely identification is:
Chryseobacterium spp
Which of the following lipoproteins will form a creamy layer at the top of stored, non-fasting plasma specimens?
Chylomicrons
Bruton's agammaglobulinemia is a:
Congenital B-cell disorder
AIDS patients have in increased susceptibility to infection due to a decrease in which of the following?
CD4+ lymphocytes
All of the following normal urine crystals are most often found in a urine specimen that has a pH > 7 EXCEPT:
Calcium oxalate
The principle behind point-of-care devices to measure hematocrit is:
Calculating the conductance of the blood sample and correcting for temperature, the conductivity of the plasma, and size of the fluid segment
An elevated level of which of the following hormones will inhibit pituitary secretion of adrenocorticotropic hormone (ACTH)?
Cortisol
From the following organisms, which one is considered to be the LEAST pathogenic to humans?
Corynebacterium ulcerans
Which is the best component to treat a patient with fibrinogen deficiency?
Cryoprecipitated AHF
Lymphocyte pleocytosis refers to a(n) _____________ in a CSF when compared to a normal sample.
Increased number of lymphocytes
Which of the following observations would best explain why a peripheral blood smear is exhibiting polychromasia?
Increased reticulocyte count
What is the probable identity of an organism isolated from a wound culture that demonstrates the following test results? Phenylalanine Deaminase = negative TSI = A/A gas Citrate = positive Lysine = positive SIM = negative/negative/negative Urea = weakly positive
Klebsiella pneumoniae
Which of the following stains is used to differentiate a neutrophilic leukemoid reaction from chronic myelogenous leukemia (CML)?
LAP
A 10-year-old male presented to the local Appalachian Mountain clinic complaining of vomiting, fever, and severe abdominal pain. Patient history revealed the child lives in substandard conditions and receives only one balanced meal per day. A stool sample was collected and submitted for parasite study. This low power view of the egg, measuring 50 µm by 35 µm, was seen in the stool concentrate. This patient is most likely infected with:
Large intestinal roundworm
The image on the right is representative of the peripheral blood smear from a five-month-old immigrant from Asia. Her mother was concerned that the child was not eating well. Her spleen was palpable. These blood count results were reported: Knowing that the family is from a region of Thailand where HbE carriers are prevalent, the physician ordered a hemoglobin electrophoresis. The hemoglobin electrophoresis detected HbE. Based on the blood count results and this representative microscopic field, which of the following peripheral blood findings should be reported?
Microcytes (microspherocytes), target cells, nucleated red blood cells
A patient presents with the following measured parameters on the complete blood count: ParameterValueReference IntervalWhite blood cells (WBC)5.6 x 109/L4.0-11.0 x 109/LRed blood cells (RBC)3.6 x 1012/L4.2-5.9 x 1012/LHemoglobin9.2 g/dL12-16 g/dLHematocrit27%37-48%MCV75 fL80-100 fLRDW-CV17%11.0-15.0% Which statement represents the patient's condition?
Microcytic, heterogenous anemia
A 45-year-old African American female has been diagnosed and treated for type 2 diabetes for the past five years. She maintains good control of her blood glucose with medication but does not exercise and has gained 12 pounds over the past year. At her next appointment, her physician orders hs-CRP along with blood assays to monitor her diabetes. Laboratory Result: hs-CRP 2.8 mg/L
Moderate risk for cardiovascular disease
Which of the following cells have a blue-gray cytoplasm with a "ground glass" appearance and vacuoles in the cytoplasm?
Monocytes
Given the following results, what is the immune status of the patient? HBsAg: negative HBeAg: negative Anti-HBc: positive Anti-HBs: positive
Recovery
A semen specimen was collected three hours before it was brought to the laboratory for examination. What course of action should be taken?
Report the specimen as compromised on the final report.
The Lecithin/Sphingomyelin (L/S) ratio determination of amniotic fluid is useful in assessing the probability of:
Respiratory distress syndrome
What molecular technique is appropriate for HIV-1 genotyping?
Reverse Transcriptase Polymerase Chain Reaction
Observed in the image is the microscopic appearance of a sporulation representative of one of the dematiaceous fungi causing chromomycosis. Note that spherical conidia are being produced laterally from the sides of a conidiophore. Which of the following choices represents the type of sporulation illustrated in this image?
Rhinocladiella sporulation
Which one of the following statements about lead poisoning is false?
Serum lead level is a good inexpensive screening test for lead toxicity
Identify the urine sediment elements shown by the arrow:
Starch crystals
What transferrin saturation level would be indicative to investigate further for hereditary hemochromatosis (HH)?
45%
A 27-year-old female presents to her physician after suffering a spontaneous abortion. Though rare, which antibody may be the etiological agent?
Anti-P
What is the approximate volume of spinal fluid in an adult?
90-150 mL
A CSF glucose value is 62 mg/dL. What would you estimate the serum glucose?
93 mg/dL
In the antibody screening test, at what phase of reactivity is it most important to read the reactions for detection of clinically significant antibodies?
AHG
A 41-year-old male arrived at the clinic with complaints of fatigue, malaise, and overall discomfort. Upon testing, the patient's CBC results were notably abnormal with 30% blasts present along with anemia and thrombocytopenia. Bone marrow and cytochemical staining were subsequently performed. The cytochemical stains noted negative reactions to Myeloperoxidase and Sudan Black B but a positive reaction to alpha-naphthyl acetate. Which of the following conditions is most likely seen?
Acute Monocytic Leukemia
What is the composition of the granules associated with basophilic stippling?
Aggregates of ribosomes
All of the following tests are affected by the pneumatic tube system transport, EXCEPT?
Alkaline phosphatase
The microscopic illustration demonstrates the golden-brown pigmented conidia and macroconidia of the following mold:
Alternaria
Which of the following is a mechanism known to cause platelet satellitosis (satellitism)?
An antibody directed against the platelet membrane
If a patient is determined to have type A blood, what antibody would be found in his/her serum?
Anti-B
Which of the following apolipoproteins contributes the greatest mass to the structure of high-density lipoprotein (HDL)?
Apo A
Identify the cell in this illustration indicated by the arrow:
Blast
What is the prominent red blood cell (RBC) morphologic feature found in lead poisoning (plumbism)?
Basophilic stippling
What is the most common Rh haplotype among whites?
DCe
All of the following are considered protected health information (PHI), EXCEPT:
Educational information
From the four specimens listed for Gram stain and culture, which one should be rejected?
Expectorated sputum in a sterile container for anaerobic culture
When vitreous fluid is collected, it must be transported to the laboratory within 15 minutes and set up immediately for culture. This specimen type must be handled with care as this specimen type is not easy to obtain. What body site is this specimen collected from?
Eye
All of the following tests will be abnormal in a patient with Stuart-Prower Factor deficiency EXCEPT?
Fibrinogen
The D-dimer is useful in detecting activity in which aspect of hemostasis?
Fibrinolysis
A laboratory test which can detect the specific decrease in the platelet surface membrane receptor glycoprotein Ib and thus lead to a diagnosis of Bernard Soulier Syndrome (BSS) is:
Flow cytometry
A direct antiglobulin test (DAT) can be used to detect all of the following EXCEPT?
IgG antibodies in the patient's serum
Which of the following methods for long-term diabetic monitoring is recommended for patients with sickle cell anemia?
Fructosamine
The image to the right is a depiction of a typical field observed on a KOH prep. What is the element observed in this image?
Fungal hyphae
Which of the following enzymes is the most sensitive indicator of long term liver damage associated with alcohol ingestion:
Gamma-glutamyl transpeptidase (GGT)
Which analyte may be falsely decreased due to a delay in transport time to the laboratory?
Glucose
A 42-year-old chain smoker experienced an increase in cough, sputum production, and intermittent shortness of breath for over one week. A diagnosis of chronic bronchitis with acute exacerbation was made. The image shows a Gram stain of an early morning, spontaneously expectorated sputum. Based on the pleomorphic coccobacilli shown in the Gram stain, what is the most likely cause of the exacerbation?
Haemophilus influenzae
Acute obstructive epiglottitis, both in adults and children, is most commonly caused by a specific bacterial species that can be recovered on chocolate agar and requires both hematin and NAD. The most likely identification is:
Haemophilus influenzae
Which of the following non-HbS hemoglobins can also sickle and show a positive solubility test?
HbC Harlem
All of the following are true about hybridization in PCR procedures, EXCEPT?
Hybridization cannot happen between a strand of DNA and a strand of RNA
The antibody mediator associated with a Type I Hypersensitivity Reaction is:
IgE
The substance produced by the pancreas and released in the bloodstream to help glucose absorption by the tissues is called?
Insulin
All of the following are causes of hypernatremia EXCEPT:
Low aldosterone production
Which type of lipoprotein transports the MAJORITY of cholesterol to cells for steroid hormone synthesis or cell membrane incorporation?
Low-density lipoproteins (LDL)
Which of the following RBC indices is expressed in femtoliters?
MCV
Creatinine excretion correlates best with which of the following parameters:
Muscle mass
Regarding therapeutic drug monitoring, which of the following statements is correct when collecting a specimen for a peak level?
Peak level is the point at which the drug is highest in the patient's body.
Which animal was involved in the reassortment of influenza A viruses that led to the 2009 novel influenza A H1N1 virus?
Pigs
There are several different types of media that can be used in electrophoresis. Most methods today use a gel - cellulose acetate, agarose, or polyacrylamide gel. Which one of the following statements is true regarding these gels?
Polyacrylamide gels have the greatest resolution or separation of solutes
In blood bank agglutination reactions, the zeta potential (a force exerted by ions in the saline solution that causes repulsion between red blood cells in the saline suspension) can be reduced by treating the sensitized cells with:
Polyethylene glycol (PEG), albumin, or proteolytic enzymes
The colonies growing on the blood agar plate, as shown in the upper image, are gray, white, and swarming. Note in the image below, that the colonies growing on XLD agar have black centers with pigmentation that does not extend into the agar. A presumptive identification of Proteus species can be made. Select the biochemical reaction that serves to separate Proteus vulgaris from Proteus mirabilis.
Positive indole
Which of the following conditions would be suggested by a jaundiced patient experiencing a marked rise in alkaline phosphatase (ALP), conjugated bilirubin, and a slight rise in alanine aminotransferase (ALT)?
Post-hepatic cholestasis
A liquid ion-exchange membrane electrode using the antibiotic valinomycin is MOST selective for:
Potassium
An electrolyte panel (lytes, chem-4) consists of:
Potassium, Sodium, Chloride, Carbon dioxide (in the form of bicarbonate)
All of the following are true in regards to performing quality control (QC) on urine chemical reagent strips, EXCEPT:
QC is performed only when patient results are questioned by the health care provider
When a Specked Nuclear Antibody (ANA) pattern is observed, what follow-up test for antibodies related to Systemic Lupus Erythematosus (SLE) is not beneficial?
Testing for antibodies to U1RNP+ and dcSSc
When is testing for weak D optional (not required)?
Testing for weak D on potential transfusion recipient samples.
A Bombay individual's blood specimen can be differentiated from a blood specimen of a group O person by which of the following?
Testing with anti-H lectin (Ulex europaeus)
When giving a whole blood donation to a patient, what consideration must be made in regards to the ABO/Rh compatibility between the recipient and the donor?
The recipient and donor ABO and Rh types must be identical.
A serum specimen for potassium testing is collected in a red top tube without a gel separator barrier. If testing is delayed by a few hours, how should the specimen be handled?
The specimen should be centrifuged as soon as it clotted and serum should be transferred to another tube.
As an RBC ages, all of the following are true EXCEPT:
They become less prone to phagocytosis.
Which of the following statements regarding the peripheral blood smear shown in the photomicrograph is TRUE?
This area is unacceptable for evaluating red blood cell morphology because it is too thin
A physician discusses weight with an overweight 60-year-old female at her yearly physical appointment. The female exercises regularly and eats healthy most of the time. The physician suggests she decrease carbohydrate intake and decrease portion size at meals. Review patient vital signs and laboratory assay results to decide if a diagnosis of metabolic syndrome is appropriate using the NCEP: ATP III Diagnostic Criteria shown on the right. Height: 5' 7'Weight: 192 lbsBMI: 30.1Waist Circumference: 37 inchesBlood Pressure: 108/70 Fasting Blood Glucose: 92 mg/dLTotal Cholesterol: 172 mg/dLLDL-C: 112 mg/dLHDL-C: 46 mg/dLTriglycerides: 70 mg/dLhs-CRP: <1.0 mg/L Which of these statements regarding this patient is true?
This patient does not meet the criteria for diagnosis of metabolic syndrome.
How is the majority of urobilinogen that is produced daily removed from the body?
Through fecal excretion
What function in the body does GGT have?
Transfer of gamma-glutamyl peptides amino acids, water, and other peptides
Although not endemic in the United States, travelers and hunters in regions of East and Central Africa may acquire this blood infection from the bite of a tsetse fly. Intermittent fever, headache, joint, and muscle pains may be experienced. In chronic cases, central nervous system symptoms such as mental retardation, tremors, and slow gait may lead to somnolence and "sleeping sickness." The invasive curved organisms as shown in this image of a Wright-stained peripheral blood smear, average 20 µm in length. What is the presumptive species identification of the hemo-flagellate related to this infection?
Trypanosoma rhodesiense
Which of these methods is used to identify prior exposure to Mycobacterium tuberculosis?
Tuberculin skin test (TST)
Nephelometry is based on the principle of:
Turbidity resulting from specific antigen-coated latex particles agglutinated by corresponding antibody
This microscopic field is representative of other fields that were observed on a Gram-stained smear. Which of the following describes the quality of the smear?
Under-decolorized; Poor Quality
Which of the following casts is characteristically associated with acute pyelonephritis?
White cell
An 8-year-old boy underwent a laparotomy for clinical signs and symptoms of acute appendicitis. Instead, the appendix did not appear inflamed, but the mesenteric lymph nodes were enlarged and edematous. The photomicrograph is a close-in H & E section of an area within one of the lymph nodes, showing hyperplasia and focal necrotizing inflammation. What bacterial species is most likely causing this reaction?
Yersinia enterocolitica
Which organism is MOST likely responsible for septic reactions associated with red blood cell transfusions?
Yersinia enterocolitica