First set of corrections from @warinner

Author: jfy133

introduction-to-ngs-sequencing.qmd

@@ -54,7 +54,7 @@ What this means is that because of this complementary pairing, regardless of whi
 
 This complementary base pairing characteristic of a DNA molecule is a critical factor of how DNA gets replicated (or copied) within a cell.
 
-At it's core, DNA replication consists of:
+At its core, DNA replication consists of:
 
 1. Unwinding the DNA helix and separating the two strands, by breaking the hydrogen bonds between the complementary bases using a helicase enzyme
 2. Using a polymerase enzyme to add complementary new 'free' nucleotides floating in the cell to the exposed base on the strand (repeating this step for each base until a 'stop' signal is received)
@@ -146,7 +146,7 @@ In 2005 the first 'Next Generation Sequencing' (NGS) machines were released ^[Wi
 
 These new sequencers were able to quickly and cheaply sequence millions of DNA molecules at once, revolutionising genetics and enabling 'accessible' genomics to a much wider group of scientists [@Koboldt2013-kk].
 
-While a few companies emerged with competing NGS sequencers employing different techniques, such as PacBio and IonTorrent, the platform that was been by far the most successful is the one from Illumina [@Heather2015-zo].
+While a few companies emerged with competing NGS sequencers employing different techniques, such as PacBio and IonTorrent, the platform that has been by far the most successful is the one from Illumina [@Heather2015-zo].
 These Illumina machines have been so successful, they have almost exclusively sequenced the entire corpus of ancient DNA sequencing data.
 Therefore the rest of this chapter will focus just on Illumina sequencing.
 
@@ -242,7 +242,7 @@ The process as depicted in @fig-intro-ngs-fig-sequencingbysynthesis can be broke
 6. Clip off the fluorophore part of the nucleotide
 7. Repeat 2-6 until the entire strand is sequenced
 
-On Illumina sequencers, the number of repetitions (known as cycles) typically happens either 50, 75, or 125 times, depending on the machine and the type of sequencing chemistry kit.
+On Illumina sequencers, the number of repetitions (known as cycles) typically happens either 50, 75, or 150 times, depending on the machine and the type of sequencing chemistry kit.
 
 We can see a small fraction of such a flow cell in @fig-intro-ngs-fig-sbsimagecapture.
 Each coloured dot corresponds to a cluster of DNA molecules.