“…Sizes of PCR products are indicated. M, FX174/HaeIII digest; +RT, reverse transcription performed in the presence of reverse transcriptase; 7RT, mock reverse transcription performed without reverse transcriptase; 7ve, PCR set up without DNA; +ve, PCR set up using genomic DNA (Fields et al, 1994) are present within the human haploid genome of 3000 Mb, giving an average gene density of approximately 23 genes per megabase. However, genes are non-randomly distributed within the genome between gene poor Giemsa dark bands, gene rich R'-bands and very gene rich sub-telomeric Tbands which are estimated to contain 9.3, 20 and 78 genes/Mb respectively (Bernardi, 1993).…”