$$T_m = 2\times (A+T) + 4\times (G+C)$$

Question 1

Which principle underlies nucleic acid hybridisation and allows probes to bind specifically to target sequences?

Accepted Answer

Complementary nitrogen base pair hydrogen bonds

Question 2

In Southern blotting, which step is essential for transferring DNA fragments from a gel to a membrane for probe hybridisation?

Accepted Answer

DNA transfer (blotting) onto nitrocellulose or nylon membrane

Question 3

A probe used in hybridisation must have which property to ensure specificity for its target?

Accepted Answer

Complementarity to the target nucleic acid sequence

Question 4

Which blotting technique is used to detect RNA molecules?

Accepted Answer

Northern blotting

Question 5

In the diagnosis of sickle cell disease using Southern blotting, which molecular event is detected?

Accepted Answer

A restriction fragment length polymorphism (RFLP) due to a mutation in the β-globin gene

Question 6

Which of the following best describes the role of microarrays in genomics?

Accepted Answer

They allow simultaneous assessment of many probes to quantify mRNA expression, DNA binding, or detect SNPs

Question 7

What is the main advantage of chromosomal microarray analysis (CMA) over metaphase plate FISH in clinical diagnostics?

Accepted Answer

CMA provides higher precision in detecting copy number variations such as deletions, insertions, and aneuploidies

Question 8

Which direct hybridisation method is used to visualise the spatial-temporal expression patterns of genes within intact cells?

Accepted Answer

Fluorescent In Situ Hybridisation (FISH)

Question 9

In a hybridisation chain reaction (HCR), what is the function of the initiator probe?

Accepted Answer

It triggers the formation of polymers of fluorescent probes, amplifying the signal

Question 10

Which equation would you use to calculate the melting temperature ($$T_m) of a $$short DNA probe for hybridisation?

Accepted Answer

$$T_m = 2	imes (A+T) + 4	imes (G+C)$$

Question 11

Which of the following is a real-world application of 'hybrid capture' hybridisation methods?

Accepted Answer

Detection of high-risk HPV for cervical cancer diagnosis

Question 12

DNA origami is a technique that allows the creation of which of the following?

Accepted Answer

2D and 3D nanoscale shapes using scaffold and staple DNA strands

Question 13

Which of the following blotting techniques is used to detect protein-protein interactions?

Accepted Answer

Far-Western blotting

Question 14

A researcher wants to detect a specific mRNA transcript in a tissue sample. Which method should they use?

Accepted Answer

Northern blotting

Question 15

Which step in the Southern blotting process ensures that only the DNA fragments of interest are visualised?

Accepted Answer

Hybridisation with a labelled probe specific to the target sequence

Question 16

Why is previous 'knowledge' of the target nucleic acid sequence necessary when designing a probe for hybridisation?

Accepted Answer

To ensure the probe is complementary and binds specifically to the target sequence

Question 17

Which of the following statements about the hybridisation chain reaction (HCR) is correct?

Accepted Answer

HCR creates polymers of fluorescent probes linked to an initiator probe, amplifying the signal

Question 18

A chromosomal microarray test detects a deletion in chromosome 17. What type of genetic variation is this?

Accepted Answer

Copy number variation (CNV)

Question 19

Which hybridisation method would be most appropriate for simultaneously assessing thousands of gene expression levels in a cancer tissue sample?

Accepted Answer

Microarray analysis

Question 20

In the context of nucleic acid hybridisation, what does probe specificity depend on?

Accepted Answer

The complementarity of the probe sequence to the target sequence

Hybridisation Methods in Molecular Biology

Study Guide - Practice Questions