MD BOC Final

Protein microarray analysis requires the use of which of the following techniques to generate protein profile data? A. Electrophoresis B. Mass spectroscopy C. Thin-layer chromatography D. Gas chromatography

B

Which method of analysis is considered the most reliable means of detecting mutations of BRCA, p53, BRAF, and other genes linked to cancer? A. FISH B. Immunohistochemistry C. Sequencing D. STR analysis

C

The mode of inheritance of mitochondrial DNA is: a. dominant b. recessive c. codominant d. maternal

D

A FISH test is performed on a slide of peripheral blood leukocytes. The test uses a dual fusion probe, consisting of a Spectrum Green labeled probe to the BCR 22 q11.2 locus, and a Spectrum Orange labeled probe to ABL 9q34. What disease is this test for? A. Chronic myelogenous leukemia B. Multiple myeloma C. Bladder cancer D. Thyroid cancer

A

A cell population is positive for surface markers CD45, CD3, CD4, and Tdt. Which type of leukocytes are these? A. Lymphocytes B. Granulocytes C. Monocytes D. Early myeloid precursors

A

Cloning a human gene into a bacterium in order to make a large molecular probe requires which vector? A. Plasmid B. Bacterial microsome C. 30S bacterial ribosome D. Single-stranded DNA

A

HLA typing can be done by which molecular method? A. PCR analysis using 96 well microtrays with allele or groups specific primers in each B. Restriction fragment length polymorphism testing C. Direct hybridization with WBCs on a peripheral blood film D. Fluorescent in situ hybridization reactions with peripheral blood lymphocytes

A

How are PCR methods adapted to yield quantitative data? A. By comparing PCR product to an internal standard B. By applying a conversion factor to the PCR signal that converts it to copies per milliliter C. By determining the mass of PCR product using ultraviolet spectrophotometry D. By making serial dilutions of the sample

A

In flow cytometry, the term "gating" refers to: A. Selection of a subpopulation of cells to count B. Determining the fluorescent emission spectrum of cells of interest C. Interference caused by binding of more than a single antibody D. Selecting the appropriate counting aperture

A

In general, which statement best characterizes the relationship between white blood cells and light scattering in flow cytometry? A. Forward scatter is related to cell size and side scatter to granularity B. Forward scatter is related to nuclear density and side scatter to size C. Forward scatter is inversely related to size and side scatter is directly related to size D. Forward scatter is related to shape and side scatter to size

A

In real-time PCR, quantitation can be done without standards of known copy number. Relative quantitation (estimated concentration) is possible because: A. Each cycle generates a twofold increase in product B. Each cycle threshold represents a 10-fold increase in product C. The fluorescence of two samples can be compared directly D. Concentration is proportional to fluorescence at the endpoint of the PCR reaction

A

In real-time PCR, what value is needed in order to determine the threshold? A. Background signal B. Melting temperature C. Maximum fluorescence D. Threshold cycle

A

In the PCR cycle, how is denaturation accomplished? A. Heat B. Alkali treatment C. Addition of sulfonylurea D. Formamide

A

Intervening sequences are found in: a. heteronuclear RNA b. mature mRNA c. ribosomal RNA d. transfer RNA

A

Polymorphisms of the cytochrome p450 genes are important in identifying which condition? A. Poor drug metabolism B. Risk for primary biliary cirrhosis C. Progression of hepatitis C to hepatic cirrhosis D. Parentage in cases where HLA results are inconclusive

A

The following figure shows DNA size standard (ladder) made by restriction enzyme digestion (PstI)of lambda phage DNA that has been separated by agarose gel electrophoresis. Which DNA band has the highest molecular weight? A. 1 B. 2 C. 3 D. 4

A

The master mix solution used for PCR contains which of the following reagents? A. Deoxyribonucleotide triphosphates B. Deoxyribonucleotide monophosphates C. Deoxyribonucleosides D. Ribonucleotide monophosphates

A

What gene must be amplified in PCR to differentiate methicillin-resistant Staphylococcus aureus from methicillin-resistant coagulase-negative Staphylococcus? A. orfX B. mecA C. VanA D. iles-2

A

What method is used to identify maternal cell contamination in amniocentesis and chorionic villus samples (CVS)? A. STR analysis B. FISH C. Microarray analysis D. MicroRNA (MiRNA) analysis

A

Which formula predicts the number of PCR products that can be produced? A. 2n where n is the number of cycles B. N4 where N is the number of cycles C. P2 + 2pq +q2 = 1 where p and q are the number of primers D. N2/2 where N is the number of cycles

A

Which is the most common method used for parentage testing in the United States? A. Short tandem repeat analysis B. Nuclear DNA sequencing C. HLA DNA typing D. Mitochondrial DNA sequencing

A

Which mechanism is responsible for retinoblastoma? A. Mutation of a tumor suppressor gene B. Mutation of a tyrosine kinase gene C. Activation of an oncogene D. Deletion of a gene encoding a GTPase activator

A

Which method has been used successfully to reduce contamination in the preamplification stage of PCR? A. Substitution of deoxyuridine triphosphate for deoxythymidine triphosphate in the master mix B. Use of low-molecular-size primers C. Use of denaturation temperature above 95℃ D. Pretreatment of samples with antisense RNA

A

Which of the following is the most common type of polymorphism? A. Single nucleotide polymorphism (SNP) B. Variable number tandem repeat (VNTR) C. Short tandem repeat (STR) D. Short repetitive interspersed element (SINES)

A

Which of the following mechanisms facilitates DNA separation by capillary electrophoresis? A. Molecular sieving B. Partitioning C. Adsorption D. Deflection

A

Which of the following thalassemias can be detected by PCR followed by blotting with a single specific oligonucleotide probe? A. α-Thalassemia B. Hemoglobin S/β-thalassemia C. β-Thalassemia D. Hemoglobin S/β-thalassemia

A

Which statement best describes the relationship between HLA DNA typing and serological haplotypes? A. One or two bands are seen for each locus correlating to reactivity with a specific antigen or group of antigens B. HLA alleles cannot be related to HLA antigens because antisera specificity is unrelated to genetic polymorphism C. A single antibody specificity always corresponds to a single allele D. Not all HLA genes produce antigens recognized by antibodies

A

Which technique is used to detect DNA containing a specific base sequence by applying a labeled probe to DNA bands immobilized onto nitrocellulose paper following electrophoresis? A. Southern blot B. Northern blot C. Dot blot D. Western blot

A

A metaphase chromosome with primary constriction that gives the chromosome clearly defined short and long arms is considered: a. acrocentric b. submetacentric c. metacentric d. telocentric

B

An RFLP is most likely detected using which of the following methods? a. Northern blot b. Southern blot c. Western blot d. Southwestern blot

B

How are cases of Duchenne's muscular dystrophy not detected by PCR usually confirmed? A. DNA sequencing B. Linkage analysis C. Macroarray analysis D. Dystrophin protein staining

B

How can a false-negative PCR test caused by the presence of an inhibitor of the reaction in a patient's sample be detected? A. Using a positive control B. Using an internal control C. Performing each test in duplicate D. Performing serial dilutions of the sample

B

How can all of the mRNA within a sample be amplified to prepare microarray probes? A. A specific primer for each mRNA must be synthesized B. A primer is made to the polyA tail of mRNA C. Nonspecific attachment of T7 polymerase occurs when the cells are treated with detergent D. Random primer sets are used under low stringency conditions

B

How can cell proliferation be explained by the BCR/ABL gene rearrangement that occurs in the 9:22 translocation that causes the Ph1 chromosome of CML? A. It causes underexpression of p53 B. A hybrid protein is made that up-regulates the cell cycle C. Translocation induces a point mutation in the ABL oncogene D. ABL activates p23

B

In PCR methods, how can several targets be copied simultaneously and detected? A. By following the increase in absorbance at 260 nm during melting B. By labeling multiple primers with specific fluors C. By substitution of hybridization proves for primers D. By analysis of adenosine tail signatures

B

In humans, which component of a gene is translated into a protein? A. Intron B. Exon C. Promoter D. TATA box

B

In microarray and macroarray analysis, which molecules are labeled? A. The immobilized DNA molecules B. The sample DNA C. Both target and sample molecules D. The substrate matrix

B

In order to prove exclusion in DNA paternity testing, why must two genes be identified that must come from the biological father and did not? A. A single exclusion can result from laboratory error B. A single exclusion can result from germ line mutation within one locus being tested C. The biological father may be a blood relative to the alleged father D. The biological mother may be different than the purported mother

B

In real-time PCR analysis, the absolute concentration of PCR product is determined by plotting which two values? A. Fluorescent intensity versus melting temperature B. The threshold cycle versus concentration C. The well factor versus concentration D. The well factor versus threshold cycle

B

The Klenow fragment of E coli DNA polymerase I is used: a. to make cDNA from RNA template b. to label DNA probes by random primer labeling c. in quantitative real time PCR d. to label a DNA probe by nick translation

B

The majority of cases of Duchenne's muscular dystrophy are caused by which type of genetic damage? A. Point mutation B. Insertion C. Deletion D. Trinucleotide repeats

B

What is a solution hybridization method for detection of nucleic acid:protein interactions? a. RNase protection assay b. gel mobility shift assay c. strand displacement amplification assay d. hybrid capture assay

B

What is the composition of the primer used in PCR? A. A cocktail of enzymes and nucleotide triphosphates that bind to the target B. An oligonucleotide complementary to bases at the 3' end of the target C. A small piece of dsDNA that attaches to the template D. A probe made of mRNA that binds downstream from the target

B

What process can be used to make a DNA probed produce a fluorescent or chemiluminescent signal? A. Enzymatic attachment of acridinium esters to terminal ends of the probe B. Substitution of biotinylated or fluorescent nucleotides into the probe C. Splicing the gene for β-galactosidase into the probe D. Heat denaturation of the probe followed by acid treatment

B

Which condition has the highest stringency for washing a Southern blot after hybridization has been completed? a. low temperature, low salt concentration b. high temperature, low salt concentration c. high temperature, high salt concertation d. low temperature, high salt concentration

B

Which method of DNA analysis is used most often to detect the hemoglobin S gene? A. FISH B. PCR followed by FRLP C. Cytogenetic analysis of chromosome 11 D. Labeled probe painting of chromosome 11

B

Which nucleotide pair has a high frequency of mutation in human chromosomal DNA? a. CC b. CG c. CA d. CT

B

Which of the following parameters are used to gate cells processed by the flow cytometer? A. Font surface fluorescence versus incident laser intensity B. Forward light scatter versus side scatter C. The ratio of light emitted at two different wavelengths D. Impedance amplitude versus background conductance

B

Which of the following types of mutation causes the premature termination of protein synthesis? A. Missense B. Nonsense C. Insertion D. Frame shift

B

Which oncogene is involved in the etiology of Burkitt's lymphoma? A. ABL B. Myc C. Ras D. HER/neu

B

Which probe is most often used to detect trisomy 21 by interphase FISH? a. locus-specific probe b. alpha satellite DNA probe c. chromosome paint probe d. spectral karyotyping probe

B

Which statement accurately describes the process of fluorescent in situ hybridization (FISH)? A. Hybridization is performed on DNA extracted from cells B. Hybridization is performed directly on intact chromosomes C. Hybridization process are attached to histones associated with the chromosomes D. Hybridization occurs by attachment to the probe only at the centromere

B

p21 is a GTP binding protein produced by which oncogene? A. RET B. Ras C. HER-2/neu D. N-Myc

B

A PCR analysis of a vaginal sample for Chlamydia trachomatis gives a negative result (optical density of biotinylated reaction product below the cutoff point). The internal control result is also below the cutoff. Positive and negative controls produced acceptable results. What action should be taken? A. The test should be reported as negative B. The sample should be diluted and the test repeated C. The result should not be reported and the sample should be repeated D. A preliminary result of negative should be reported but should be confirmed by further resting using a different method of analysis

C

A PCR reaction is performed, and the negative control demonstrates the presence of a detectable number of PCR product (amplicons) by capillary electrophoresis. What is the most likely cause? A. False-positive post-PCR hybridization reaction due to low stringency B. Dimerization of PCR primers C. Contamination of control sample with a trace amount of template DNA D. Background signal from gel fluorescence or inadequate removal of unbound probe

C

A tissue sample for DNA analysis by PCR was processed for DNA by simple lysis and proteinase K digestion. The lysate was diluted 1:100 and its absorbance measured in an ultraviolet spectrophotometer at 260 nm and 280 nm. The absorbance ratio 260:280 was 1.2. What does this indicate? A. The DNA concentration is too high for PCR B. The DNA concentration is too low for PCR C. The sample contains too much protein D. The sample is optimal for PCR

C

An assay based on the principle of proteomics may be used for which of the following? A. Screening for colorectal cancer B. Screening for lung cancer C. Identifying malignant ovarian masses D. Identifying malignant breast tumors

C

Approximately how may mutation have been identified in the gene coding for the cystic fibrosis trans membrane conductor regulator protein (CFTR)? A. 10 B. 100 C. 1,000 D. 10,000

C

Chelex® 100 resin is used to: a. purify mRNA from total RNA b. extract total RNA from cells c. extract DNA from cells d. remove unincorporated primers from PCR reaction prior to gel analysis of PCR products

C

Fluorescent dyes most commonly conjugated to antibodies used in flow cytometry are: A. Fluorescein isothiocyanate and Texas red B. Calcofluor white and Texas red C. Phycoerythrin and fluorescein isothiocyanate D. Acridine orange and rhodamine

C

How can PCR be applied to the detection of human immunodeficiency and other RNA viruses? A. The virus must be inserted into human DNA by viral integrase prior to PCR B. Substitute deoxyuridine triphosphate in place of deoxythymidine triphosphate in the master mix C. Add a heat-stable reverse transcriptase enzyme to the master mix D. Substitute ribonucleotide triphosphates for deoxyribonucleotide triphosphates in the master mix

C

How can cell proliferation be explained by the BCL 2 translocation t(14;18) that occurs in up to 90% of persons with follicular B-cell lymphoma? A. p53 is underexpressed B. A hybrid protein is made that up-regulates the cell cycle C. Transcription of the BCL 2 oncogene is increased by the translocation D. The BCL 2 gene joins with the p21 gene, making it inactive

C

How many volumes of ethanol are added to 1 volume of a DNA:salt solution to cause the DNA to precipitate? a. 1 b. 1.5 c. 2 d. 2.5

C

In situ hybridization (ISH) test for human papilloma virus (HPV) using cervical smears differ from immunochemical staining of tissue in which regard? A. ISH has lower analytical sensitivity B. ISH has lower analytical specificity C. ISH differentiates subtypes more easily D. ISH differentiates cervical neoplasia from genital warts

C

Inheritance of BRCA1 or BRCA2 mutations increases the risk of breast and ovarian cancer by which mechanism? A. Oncogene production B. Transcription signaling by the mutant protein C. Deficient tumor suppressor function D. Chimeric protein production

C

Reverse transcriptase would best be described as: a. DNA-dependent DNA polymerase b. DNA-dependent RNA polymerase c. RNA-dependent DNA polymerase d. RNA-dependent RNA polymerase

C

The 2 alleles for a sex-linked recessive disease are X and x. The mutant allele is x. What is the percentage of male offspring that would be expected to be affected by the disease form parents who have the following genotypes? mother: Xx father: xY a. 0 b. 25 c. 50 d. 100

C

The polymerase chain reaction (PCR) involves three processes. Select the order in which these occur. A. ExtensionàAnnealingàDenaturation B. AnnealingàDenaturationàExtension C. DenaturationàAnnealingàExtension D. DenaturationàExtensionàAnnealing

C

What is the clinical significance of K-ras testing? A. K-Ras mutations make tumor cells more susceptible to chemotherapy B. K-Ras is a tumor suppressor gene and mutations are associated with increased lifetime risk of malignancy C. K-Ras mutations result in treatment resistance to growth factor receptor inhibitors D. K-Ras is sued to identify the tissue of origin

C

What is the difference between a microarray and a macroarray DNA assay? A. The number of targets is larger on a macroarray B. The molecular size of each target is larger on a macroarray C. The amount of each target is larger on a macroarray D. The substrate used for a microarray is different from a macroarray

C

When quantifying the amount of genomic DNA in a sample by spectrophotometry, an OD 260 of 1.0 corresponds to what concentration of DNA? a. 10 µg/mL b. 20 µg/mL c. 50 µg/mL d. 100 µg/mL

C

Which double-stranded DNA molecule has the highest melting temperature? A. An oligonucleotide with a repeating sequence of A-A-A at the 5' end B. A molecule of 5,000 base pairs with a high number of A-T base pairs C. An oligonucleotide with a large number of repeating C-G-C codons D. A DNA polymer of 100,000 base pairs

C

Which is considered an epigenetic modification of DNA? a. a transversion of an A nucleotide to a T in an exon of a gene b. a transition of an A to a G in an intron of a gene c. methylation of CpG islands in the promoter region of a gene d. insertion of a nucleotide into the coding region of a gene

C

Which method is most useful for confirmation that a culture isolate is Group B streptococcus? A. Southern blotting B. Polymerase chain reaction C. Direct hybridization D. Probe capture assay

C

Which of the following genetic diseases is caused by an expanded trinucleotide repeat? A. Prader-Willi syndrome B. Angelman's syndrome C. Fragile X syndrome D. Williams' syndrome

C

Which real-time PCR parameter can be used to detect the presence of a contaminant? A. Threshold cycle B. Baseline C. Melting temperature D. Relative fluorescent intensity

C

Which statement about CF is accurate? A. A sweat chloride test is abnormal in all forms of CF B. Immunoreactive trypsin is deficient in all persons with CF C. Some CF mutations can cause male infertility with no other symptoms D. The CF genotype always predicts the severity of the disease

C

Which statement bests describes real-time PCR testing for Mycobacterium tuberculosis? A. The test is positive only in cases of smear-positive and culture-positive infections B. The test has a sensitivity of > 99% on all specimen types when compared to culture C. The test can detect 85%-90% of smear-negative, culture-positive infections D. The test sensitivity is near 100% but specificity is approximately 80%

C

Which statement concerning the resolution of DNA on an agarose gel is true? a. the polymerization of agarose is initiated by adding TEMED and ammonium persulfate to agarose monomer in solution b. agarose gel electrophoresis can resolve smaller molecules of DNA compared to acrylamide gel electrophoresis c. as the concentration of agarose in the gel increases, the smaller the size of DNA that can be resolved on the gel d. DNA must be denatured before loaded into the sample wells of an agarose gel

C

Why is the unique characteristic of the DNA polymerase, Taq DNA polymerase, used in PCR? A. It can be enzyme labeled B. It is more efficient than eukaryotic polymerases C. It is heat stable D. It works with DNA of any species

C

All of the following are requirements for reducing contamination in DNA amplification methods except: A. Use of aerosol barrier pipette tips when transferring samples or reaction product B. Preparation of reagents in a dead air box or biological cabinet C. A separate area for performing preamplification, postamplification, and detection steps D. Pretreatment of sample with high-intensity ultraviolet light

D

During the G2 phase of the cell cycle, the DNA content of a cell is: a. haploid b. diploid c. triploid d. tetraploid

D

FISH can distinguish each of the following chromosomal abnormalities except: A. Aneuploidy B. Translocation C. Deletion D. Trinucleotide repeats

D

Hereditary hemochromatosis is the result of which type of mutation? A. Nonsense mutation B. Microdeletion C. Translocation D. Single nucleotide substitution

D

Highest-resolution HLA typing is needed for which of the following transplants? A. Heart B. Liber C. Kidney D. Bone marrow

D

In real-time PCR, which of the following methods is not based on using a probe? A. TaqMan B. Molecular beacon C. Scorpion D. SYBR green

D

The fluorescent dye that exhibits the greatest sensitivity for quantization of DNA is: a. ethidium bromide b. Hoechst 33258 c. propidium iodide d. SYBR® Green

D

The methodology of performing a revers dot blot is best described as: a. attaching many patient DNA samples to a nitrocellulose membrane and hybridizing the patient samples with a single labeled probe b. attaching multiple patient samples to a nitrocellulose membrane and hybridizing multiple labeled probes to the patient samples c. attaching multiple labeled probes to a nitrocellulose membrane and hybridizing a patient sample to the multiple labeled probes d. attaching multiple probes to a nitrocellulose membrane and then hybridizing a single labeled patient sample to the multiple probes

D

The term that best describes males regarding X-linked genes is: a. heterozygous b. homozygous c. haplozygous d. hemizygous

D

What reagent is most commonly used to stain DNA separated by electrophoresis? A. Silver nitrate B. Nicotinamide adenine dinucleotide C. Cationic dye D. Ethidium bromide

D

What term describes the products produced when DNA is digested by restriction endonucleases? A. Mosaicisms B. Chimeras C. Amplicons D. Restriction fragment length polymorphisms

D

Which base pair sequence is most likely to serve as a binding site for a restriction endonuclease? A. A-T-T-C-A T-A-A-G-T B. C-T-A-C-T-G G-A-T-G-A-C C. C-A-C G-T-G D. A-A-G-C-T-T T-T-C-G-A-A

D

Which is most sensitive methods of minimal residual disease testing in chronic myelogenous leukemia? A. Karyotyping analysis B. FISH C. Flow cytometry D. RT-PCR

D

Which method is most sensitive for detection of viral meningitis? A. Viral culture B. CSF WBC count C. Specific antibody testing of CSF for viral antigens D. Real-time RT-PCR

D

Which method is used to determine if the hemoglobin C gene is present in fetal cells? A. Chromosome painting B. FISH C. Restriction enzyme analysis D. PCR followed by blotting with a specific oligonucleotide probe

D

Which of the following alleles has the highest frequency in the general population? A. ΔF508 (cystic fibrosis) B. Factor V-Leiden (hereditary thrombophilia) C. Prothrombin G20210A (hereditary thrombophilia) D. Methylene tetrahydrofolate reductase mutation C677T homocysteinemia

D

Which statement accurately describes the clinical utility of translocation testing in leukemia? A. Relapse is predicted by any new translocation occurring after treatment B. Specific translocations associated with a type of leukemia will occur in all cases C. Translocation products for each leukemia subtype are always the same D. Translocation is a sensitive way to identify surviving leukemic cells following treatment

D

Which statement best describes the method of branched DNA signal amplification? A. The DNA template is amplified directly using patented enzymes B. Multiple primers are used to create branches of the template DNA, permitting multiple extension sites C. The target DNA is denatured and hybridized to RNA, and the hybrid molecules are amplified by both DNA and RNA polymerases D. The target DNA is bound by multiple probes, and those are amplified instead of the target DNA

D

Which statement bet describes a DNA polymorphism? A. A point mutation arising in a gene B. Any change in DNA that is associated with abnormal function C. A change in the base sequence of DNA that Is translated into an abnormal protein D. A variation in DNA that occurs with a frequency of at least 1%

D

Which type of specimen would be unsuitable for FISH analysis? A. Paraffin-embedded tissue B. Cells with chromosomes in metaphase C. Cells with chromosomes in interphase D. A cell suspension containing maternal and fetal blood

D