tokens: Northern blot and reverse transcription-PCR analyses of human mRNA samples demonstrate that RNR is expressed exclusively in the retina , with transcripts of approximately 7.5 kb , approximately 3.0 kb , and approximately 2.3 kb by Northern blot analysis .
folded_tokens: northern blot and reverse transcription-pcr analysis of human mrna sample demonstrate that rnr be express exclusively in the retina , with transcript of approximately 7.5 kb , approximately 3.0 kb , and approximately 2.3 kb by northern blot analysis .