MOLBIO FINALS Flashcards by Merphy Papin

DNA extraction from plant tissues are
difficult due to

Presence of secondary metabolism and
polysaccharides

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In inorganic extraction of RNA, proteins and
DNA are precipitated using

High Salt Concentration

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A ready-to-use reagent used for cell lysis for
RNA extraction

TRizol

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What method does not provide efficient
recovery of clean DNA

Inorganic Extraction

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In this step, the cell and the nucleus are
broken open to release the DNA inside

Lysis

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How would you interpret the extracted
sample if 260/280 ratio is too low <1.8?

Protein Contamination

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Which of the following is not acceptable for
DNA extraction?

The flow-through is discarded after the
addition of elution buffer

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Clear liquid that lies above the solid
residue after centrifugation

supernatant

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An enzyme that degrades RNA

RNAses

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What is added to ensure the stability of the
DNA

TE buffer

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Fidelity in amplification may be decreased
in which of the following conditions

Increased concentrations of dNTPs

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Low to no yield of PCR products may be a
result of which of the following

Decreased MgCl2+ and decreased
dNTPs

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What would be the effect on the PCR
reaction if any of the following
circumstances arose: 1) There are no
primers in the reaction, 2) enough dNTPs in
the reaction, 3) there is Taq polymerase in
the reaction

PCR would proceed normally

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Pfu polymerase is superior over Taq
polymerase because

of more accurate amplification

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At what temperature does annealing of
primers to the template takes place
A. 5 Degrees Celsius the melting point
of primer
B. 47-60 C
C. 10-20 C below the melting point of
primers

Ans. A, B and C
A. 5 Degrees Celsius the melting point
of primer
B. 47-60 C
C. 10-20 C below the melting point of
primers

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A method that requires a set of four
specifically designed primers that can
recognize six distinct regions on the target
DNA

LAMP

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After heating and cooling the mixture,
which of the following catalyzes the
synthesis of complementary strands of
DNA?

Taq polymerase

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Which of the following PCR Techniques is
used for mass testing for COVID19
infection?

Reverse Transcription Real-time PCR

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The PCR technique was developed by:

Mullis

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An enzyme that uses RNA as the template
to make complementary DNA (cDNA)

Reverse Transcriptase

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Each band on the gel represents a different
protein (or protein subunit); _____ proteins
move through the gel more _____
than_____ proteins and therefore are found
nearer the _____ of the gel.

Smaller, rapidly, larger, bottom

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Plastic combs are used to create
indentations, or wells, into which the DNA is
loaded

True

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Which of the following is the most
preferred buffer condition for agarose gel
electrophoresis?

Buffer of pH 7

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Unknown samples are often run alongside a
DNA Ladder, containing known lengths of
DNA for comparison. The gel is then placed
in a container, called a gel tank or box, filled
with conductive, pH controlled buffer
solution, usually Tris-acetate- EDTA or TrisBorate-EDTA and an electrical field is
applied along the length of the gel.

Both Statements are true

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Which the following statements is/are true about the stacking gel? i. The stacking gel solution contains acrylamide. ii. It is on the top of the separating gel. iii. It is used to dilute the protein sample before it enters the main separating gel. iv. It is into this gel that the wells are formed and the proteins loaded.

i, ii, & iv only

Electrophoresis can be used in a range of diagnostic tests, primarily in the screening of genetic disorders but also to identify abnormal proteins.

True

The following basic reagents required for agarose gel electrophoresis are: 1. The agarose powder, to make the gel; 2.Buffer stocks to make the running buffer; 3. Loading dye to mix with DNA & DNA Ladders to compare DNA lengths; 4. DNA stain for visualizing DNA

1,2,3,4

In SDS-PAGE, protein sample is first treated with detergent sodium dodecyl sulfate (SDS), in order to:

Make the protein become negatively changed

The sample is then fractionated by electrophoresis through a _______. As all the proteins now have an _______ to mass ratio, they are separated on the basis of their _____.

Polyacrylamide gel, identical charge, mass

If 2% (w/v) of agarose in gel is used, what is the effective separation size range of double-stranded DNA?

0.1 – 3 kb

Place the following steps in MALDI-TOF in their correct sequence. 1 Vaporized ions travel towards the detector. 2 Sample is vaporized 3 The matrix absorbs the ultraviolet light and converts it to heat energy 4 The sample for MALDI is uniformly mixed in a large quantity of matrix.

4321

Cuvette of choice for measurement of proteins

Glass

The end color of Lowry Method if positive for protein

Blue-green color

In the experiment, product formation (monitored as color intensity) is _________ the concentration of the antigen (BSA) solution in the sample.

Proportional to

The most frequent application of agarose gel electrophoresis is in molecular cloning. This is the construction of recombinant DNA molecules that are integrated into various organisms to create genetic modifications.

Both statement are true

ELISA (enzyme-linked immunosorbent assay) allows for rapid screening and quantification of the presence of _______ in a sample.

Antigen

Affinity chromatography relies on

Ligand binding abilities

In Western blot technique, the protein is specifically detected by reacting it with:

Labeled antibody

In order to stop the reaction between enzyme and substrate, what process is needed?

Add strong acid to sample

The most popular method used with proteomic analysis

Reverse phase HPLC

Which of the following statements about agarose gel electrophoresis is false?

Under the influence of the electric field, positively charged DNA will migrate towards the negative charged end of the gel. * DNA is negative charged bc of phosphate

Which of the following is an example of fluorescent dyes for protein?

NilleRed * cydyes * sypro

The higher the mass, the longer the time of flight

MALDITOF-MS

To apply an electrical field to the gel, you will not need an electrophoresis power supply. The gel tank, also called a gel box, is the main component of the horizontal agarose gel electrophoresis system.

the first statement is false and second statement is true

Which of the following amino acid residues cannot absorb light at 280nm?

- Tyrosine - Tryptophan - Phenylalanine

Please arrange the following steps about ELIZA (Enzyme-linked immunosorbent assay) in chronological order i. incubate with antibody-enzyme complex that binds primary antibody. ii. coat surface with antigen, block unoccupied sites with nonspecific protein. iii. add substrate, formation of colored product indicates presence of specific antigen. iv. incubate with primary antibody against specific antigen

iii. add substrate, formation of colored product indicates presence of specific antigen

Large molecules move through column more quickly - small molecules are trapped inside the beads

Size Exclusion Chromatography

Which of the following will not affect the rate of migration of DNA in agarose gels

DNA Concentration

What is the role of goat anti-rabbit IgG horseradish peroxidase conjugate in the experiment?

Secondary Ab

What is the purpose of using bromophenol blue in the sample buffer?

To monitor the electrophoresis run

Special Sample Requisition (Pacific Biosciences RS II) EXCLUDE:

Single stranded format of RNA

Which of the following statements is CORRECT?

Pre analytical standards aim at quality, format, and amount of specimen/sample which should be documented in detail OR The analytical analysis mainly focuses on the documentation and bioformatics process

External Quality Assurance is also known as

Proficiency Testing

His task is to take charge of participation and performance in quality assurance schemes and to organize internal and external audits. NO MORE THAN 2 WORDS. ALL CAPS

QUALITY ASSURANCE

In choosing the right analytical test, what factor should we consider?

Amount of tissue available OR amount of kits available

Sample handling and receipt must follow what ISO number?

15189

What does TAT stands for? (all caps; add space with every word)

TURN AROUND TIME

All preventive maintenance and calibrations must be scheduled and performed at least as frequently as suggested by the equipment manufacturers to ensure continued accuracy, precision, and extended usable life of the equipment in EQA programs.

True

Which of the following statements is CORRECT?

The goal of the molecular diagnosis procedure is to select the right test for each patient, generating accurate, clinically relevant results to optimally influence clinical care and conserve health care resources

NABs perform surveillance in laboratories every _ to _ years?

1-2

Sequence alignment will give you information such as the following EXCEPT

Location of the gene in the chromosome

In sequence alignment, the identity of two residues (bases or amino acids) is indicated by

Vertical line

This is a method that positions the building blocks (bases or amino acids) of biological sequences in order to identify regions of similarity that may have consequences for functional, structural, or evolutionary relationships.

Sequence alignment

If you want to compare the DNA sequences of a gene found in a man and a mouse to determine if they have the same function, which tool will you use?

EMBOSS Water

Which is most critical in determining annealing temperature of primers?

The melting temperature

Which is true about primer length in PCR?

Longer primers provide adequate specificity compared to shorter ones

Which double-stranded DNA molecule has the highest melting temperature?

An oligonucleotide with a large number of repeating C-G-C codons

When you want to align several DNA sequences, which tool will you use?

MUSCLE

Which of the following provides the amino acid sequence and crystal structure of a protein?

PDBj

When you searched GenBank for the DNA sequence of gene X, the coding sequence of the that gene may be obtained by clicking which feature of the search result

Cds

When you do a BLAST search for a DNA sequence, which shows a summary table of all the alignments, sequence homology to the Query sequence with the subject sequence, and the Accession number?

Description Text Box

Which GC content of primers is LEAST desirable for a PCR?

38 percent

Which will promote primer dimer formation?

A run of Gs at the 3-prime end - hairpin

Which is INCORRECT regarding designing of primers?

The reverse primer is derived from or before the 5-prime sequence of the target DNA. 3' to '5

In the GASDirect test for the identification of Group A Streptococcus, the nucleic acid probe used is:

Single stranded enzyme labelled nucleic acid probe OR Single stranded chemiluminescent

DNA target/s for the molecular detection of fungal infection

rDNA

Highest amount of DNA is found in which of the following samples?

Blood

If one is handling a skin biopsy for molecular assay, the proper handling temperature for the said sample is:

On ice

Main advantage of using Interphase – FISH is:

No cell culture is required

In order to achieve a purified protein extract for MALDI – TOF MS, which of the following is commonly added along with the matrix?

Formic Acid

Advantage/s of F-ISH

Ans. A and B A. Automated method may be applied B. Able to distinguish one disease from another

- Diagnosis of inherited diseases - Evaluate remission of disease

Application/s of F-ISH /s of F-ISH

If one is handling a heparinized peripheral blood for molecular assay, the proper handling temperature for the said sample is:

Room temperature

Advantage/s of using whole genome sequencing (WGS) for detecting MRSA

A. Virulence of the strain may be assessed B. Prediction of resistance is possible

These are short sequences of bases that repeat many times in a row which act as fillers or spacers between the coding portions of the chromosome.

Satellite DNA

Sample/s that may be used for forensic investigations

A. Bone B. Hair C. Blood

Most widely applied NAAT for the diagnosis of Mycoplasma pneumoniae is:

PCR

When using the LAMP method for the identification of Streptococcus agalactiae, the probes used targets which of the following gene?

cfb gene

Modification of F-ISH wherein multiple probes are used for a single chromosome

Multicolor FISH

Which of the following is extracted for MALDI – TOF MS microbial identification?

Protein

Specimen that is used for the prenatal analysis of possible chromosomal abnormalities

Amniotic Fluid

The most important pre-analytical consideration for the successful microbial identification using MALDI-TOF is:

Sample Extraction

Screening for the possible colonization of Streptococcus agalactiae using molecular assays is needed for which group of population?

Pregnant individual at 35th – 37th week of gestation

ompA gene is used as a target gene for the identification of the different serovars of which bacteria?

Chlamydia Trachomatis