Question

1.expressed sequence tags (ESTs) are synthesized and spotted onto glass slides 2.cDNA made from RNA of two cell sources, labeled with diff fluorescent dyes 3.cDNAs pooled and hybridized to ESTs on chip excitation and measurement of intensities of fluorescence (therefore degree of hybridization of each sample's cDNA to each EST)

Answer 1

The question revolves around the use of expressed sequence tags (ESTs) and fluorescent dyes in DNA microarray analysis to study gene expression through the hybridization of cDNAs to ESTs, followed by fluorescence intensity measurement.

Step-by-step explanation:

Expressed sequence tags (ESTs) are short DNA sequences derived from cDNA that are used to identify gene transcripts, and they play a crucial role in the process of hybridization on DNA microarrays. The procedure entails synthesizing and spotting ESTs onto glass slides, then creating cDNA from the RNA of two cell sources, each labeled with different fluorescent dyes. After pooling together, the cDNAs are hybridized to the ESTs on the chip, and subsequently, the degree of hybridization is determined by measuring the intensities of fluorescence.

These steps can be further understood by noting that genomic DNA or mRNA is isolated, reverse-transcribed to cDNA, labeled with fluorescent dyes for visualization, and combined for hybridization to the microarray chip. The hybridization events are monitored by measuring the intensity of fluorescence at specific spots, providing insights into gene expression levels and interactions within the examined cells.