What are the three limitations of the DNA Microarray?
What are the three limitations of the DNA Microarray?
The most significant disadvantages of microarrays include the high cost of a single experiment, the large number of probe designs based on sequences of low-specificity, as well as the lack of control over the pool of analyzed transcripts since most of the commonly used microarray platforms utilize only one set of …
Which of the following is incorrect about a microarray?
1. Which of the following is incorrect about a microarray? Explanation: The entire cDNA population, labeled with fluorescent dyes or radioisotopes, is allowed to hybridize with the oligo probes on the chip. Explanation: The oligonucleotides are called probes that hybridize to labeled cDNA samples.
Why is cDNA used in microarray?
The cDNA microarray is the most powerful tool for studying gene expression in many different organisms. It has been successfully applied to the simultaneous expression of many thousands of genes and to large-scale gene discovery, as well as polymorphism screening and mapping of genomic DNA clones.
How is a microarray analyzed?
To perform a microarray analysis, mRNA molecules are typically collected from both an experimental sample and a reference sample. For example, the reference sample could be collected from a healthy individual, and the experimental sample could be collected from an individual with a disease like cancer.
What is the advantage of DNA microarrays over other methods to study gene transcription?
The microarray assay is a powerful molecular technology that allows the simultaneous study of the expression of thousands of genes or their RNA products, giving an accurate picture of gene expression in the cell or the sample at the time of the study.
What is the advantage of the use of a DNA microarray?
DNA microarrays are mainly used for transcriptional profiling but they can also permit large-scale study of DNA variations, rapid investigation of chromosomal structure and a global identification of protein-binding sites on DNA.
What will be the consequences of not having an origin of replication ORI in the vector?
What will be the consequence of not having an origin of replication (ori) in the vector? Explanation: In the case ori is absent, the vector won’t be able to replicate. As the replication won’t take place, only one of the daughter cells would be having the vector. A colony of transformed colonies won’t be obtained.
Which of the given statement is incorrect about microarray analysis?
Which of the given statements is incorrect about Microarray Analysis? Explanation: Microarray analysis is designed to detect global changes in transcription in a genome but does not provide information about the levels of protein products of the genes, which may also be subject to translational regulation.
Why we use cDNA instead of DNA?
There are several advantages to using cDNA as opposed to genomic DNA for doing this: No introns: Eukaryote genes commonly contain introns (non-coding sequences). These are removed after mRNA synthesis so cDNA contains no introns. This means that a cDNA copy of a gene can be isolated as a single, intron-free fragment.
What is the principle of microarray?
The principle behind microarrays is that complementary sequences will bind to each other. The unknown DNA molecules are cut into fragments by restriction endonucleases; fluorescent markers are attached to these DNA fragments. These are then allowed to react with probes of the DNA chip.
Why is a microarray useful in examining gene expression?
Why are Microarrays Important? Microarrays are a significant advance both because they may contain a very large number of genes and because of their small size. Microarrays are therefore useful when one wants to survey a large number of genes quickly or when the sample to be studied is small.
What is microarray analysis and its application?
Microarray can be a boon to researchers as it provides a platform for simultaneous testing of a large set of genetic samples. Gene microarrays have been used for comparative genomic hybridization. In this technique, genomic DNA is fluorescently labeled and used to determine the presence of gene loss or amplification.
How are DNA microarrays used in medical research?
Microarrays can also be used to study the extent to which certain genes are turned on or off in cells and tissues. In this case, instead of isolating DNA from the samples, RNA (which is a transcript of the DNA) is isolated and measured. Today, DNA microarrays are used in clinical diagnostic tests for some diseases.
How is normal DNA labeled in DNA microarray?
The individual’s DNA is labeled with green dye and the control – or normal – DNA is labeled with red dye. Both sets of labeled DNA are then inserted into the chip and allowed to hybridize – or bind – to the synthetic DNA on the chip.
How does a DNA microarray bind to a DNA chip?
Both sets of labeled DNA are then inserted into the chip and allowed to hybridize – or bind – to the synthetic DNA on the chip. If the individual does not have a mutation for the gene, both the red and green samples will bind to the sequences on the chip that represent the sequence without the mutation (the “normal” sequence).
Is it possible to detect mutations in DNA?
Scientists know that a mutation – or alteration – in a particular gene’s DNA may contribute to a certain disease. However, it can be very difficult to develop a test to detect these mutations, because most large genes have many regions where mutations can occur.
