I'm guessing this is something I should just know. However, I'm helping QC some new ssRNA libraries and we are confronting some questions about ribosomal RNA.
I was hoping I could find the sequence for 18S or 28S in the hg19 reference (perhaps my first mistake). It turns out that the 18S and 28S sequences blast really well to gl000220, but I haven't found any annotation in the area suggesting that it is appropriate to consider the coordinates on gl000220 as representing the ribosomes.
So, is it appropriate to look for 18S and 28S in hg19? If so, are they annotated in any particular area?