PMID- 25542136 OWN - NLM STAT- MEDLINE DCOM- 20160222 LR - 20181113 IS - 1573-4994 (Electronic) IS - 1053-0509 (Linking) VI - 25 IP - 1 DP - 2015 Jan TI - An acridine orange spore germination fluorescence microscopy versus spectral paradox. PG - 211-6 LID - 10.1007/s10895-014-1498-5 [doi] AB - The metachromatic fluorophore acridine orange (AO) has demonstrated green fluorescent staining of dormant Bacillus spores and orange to red staining of transcriptionally active vegetative cells when used in the mid-micoMolar range. Despite the microscopic observation of numerous bright orange to red fluorescent vegetative cells following germination induction, no clear spectral emission peaks > 590 nm have ever been reported for spectrofluorometric analysis involving AO in conjunction with spore germination. This microscopy versus spectrofluorometry paradox is documented in the present report and hypotheses are put forth to explain the very weak spectral changes in the red region which do not appear to correlate with the abundant orange-red fluorescence of nascent vegetative cells seen through the fluorescence microscope. FAU - Bruno, John G AU - Bruno JG AD - Operational Technologies Corporation, 4100 NW Loop 410, Suite 230, San Antonio, TX, 78229, USA, john.bruno@otcorp.com. LA - eng PT - Comparative Study PT - Journal Article DEP - 20141228 PL - Netherlands TA - J Fluoresc JT - Journal of fluorescence JID - 9201341 RN - F30N4O6XVV (Acridine Orange) SB - IM MH - Acridine Orange/*chemistry MH - Bacillus thuringiensis/*cytology/*physiology MH - Microscopy, Fluorescence MH - Spectrometry, Fluorescence MH - Spores, Bacterial/cytology/physiology EDAT- 2014/12/30 06:00 MHDA- 2016/02/24 06:00 CRDT- 2014/12/28 06:00 PHST- 2014/10/11 00:00 [received] PHST- 2014/12/05 00:00 [accepted] PHST- 2014/12/28 06:00 [entrez] PHST- 2014/12/30 06:00 [pubmed] PHST- 2016/02/24 06:00 [medline] AID - 10.1007/s10895-014-1498-5 [doi] PST - ppublish SO - J Fluoresc. 2015 Jan;25(1):211-6. doi: 10.1007/s10895-014-1498-5. Epub 2014 Dec 28.