scholarly journals The ratio of RNA to total nucleic acid content as a quantitative measure of unbalanced cell growth

Cytometry ◽  
2005 ◽  
Vol 2 (4) ◽  
pp. 212-218 ◽  
Author(s):  
Frank Traganos ◽  
Zbigniew Darzynkiewicz ◽  
Myron R. Melamed
1950 ◽  
Vol 0 (0) ◽  
pp. 3151-3155 ◽  
Author(s):  
P. C. Caldwell ◽  
E. L. Mackor ◽  
Cyril Hinshelwood

1973 ◽  
Vol 21 (7) ◽  
pp. 628-633 ◽  
Author(s):  
ALFREDO MARIANO GARCIA ◽  
PATRICIA A. N. SULLIVAN

Rat mononuclears (lymphocytes and monocytes) were studied for total nucleic acid content by means of ultraviolet cytophotometry. Another set was treated with ribonuclease, and deoxyribonucleic acid (DNA) was measured using the same technique. It was found that total nucleic acid content (DNA and RNA) increases linearly with cell size from about 20 units in lymphocytes having 5 µ in diameter up to around 30 units in cells having 12-14 µ in diameter; this is to say, an almost 50% increase for a 6-7-fold enlargement. After ribonuclease treatment, however, the value of the integrated extinction (DNA) tends to remain constant for different cell sizes. A 650% variation in area is accompanied by a DNA change of less than 6%. The differences between treated and nontreated cells are nonsignificant for populations having up to 7.0-7.5 µ in diameter, which implies that small lymphocytes either have a negligible amount of RNA or that the instrument is not sensitive enough to detect it (less than 7% of the DNA content, this figure being the random error of our technique). These differences become highly significant for mononuclears having 8 µ or more in diameter. Therefore, while DNA tends to be constant and independent from cell size, RNA content tends to be harmoniously inconstant, since it is correlated with cell (and nuclear) size and degree of chromatin diffusion.


1956 ◽  
Vol 144 (917) ◽  
pp. 520-527 ◽  

Total nucleic acid (TNA) and deoxyribonucleic acid (DNA) of degenerating and stimulated sciatic nerves of rabbits have been determined. The ratio DNA/TNA in normal nerves was 0·59. In degenerating nerve the total nucleic acid content increased during the first 96 h, though there was little increase in DNA, the increase being presumably mainly in the fraction containing ribonucleic acid (RNA). On the contralateral side the TNA content remained unchanged, but the DNA/TNA ratio decreased to a small extent. After stimulation of the sciatic nerve for 4 h TNA remained unchanged but DNA decreased markedly.


1957 ◽  
Vol 12 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Nobuyasu KAWASAKI ◽  
Ichiro TAKI ◽  
Chiaki WATANABE ◽  
Kiyoshi MATOBA ◽  
Mokichiro NISHIO ◽  
...  

2018 ◽  
Author(s):  
Arnaldo Negron ◽  
Natasha DeLeon-Rodriguez ◽  
Samantha M. Waters ◽  
Luke D. Ziemba ◽  
Bruce Anderson ◽  
...  

Abstract. The abundance and speciation of primary biological aerosol particles (PBAP) is important for understanding their impacts on human health, cloud formation and ecosystems. Towards this, we have developed a protocol for quantifying PBAP collected from large volumes of air with a portable wet-walled cyclone bioaerosol sampler. A flow cytometry (FCM) protocol was then developed to quantify and characterize the PBAP populations from the sampler, which were confirmed against epifluorescence microscopy. The sampling system and FCM analysis were used to study PBAP in Atlanta, GA over a two-month period and showed clearly defined populations of DNA-containing particles: Low Nucleic Acid-content particles (bioLNA), High Nucleic Acid-content particles (HNA) being fungal spores and pollen. We find that daily-average springtime PBAP concentration (1 to 5 μm diameter) ranged between 1.4 × 104 and 1.1 × 105 m−3. The BioLNA population dominated PBAP during dry days (72 ± 18 %); HNA dominated the PBAP during humid days and following rain events, where HNA (e.g., wet-ejected fungal spores) comprised up to 92 % of the PBAP number. Concurrent measurements with a Wideband Integrated Bioaerosol Sensor (WIBS-4A) showed that FBAP and total FCM counts are similar; HNA (from FCM) significantly correlated with ABC type FBAP concentrations throughout the sampling period (and for the same particle size range, 1–5 μm diameter). However, the FCM bioLNA population, possibly containing bacterial cells, did not correlate to any FBAP type. The lack of correlation of any WIBS FBAP type with the bioLNA suggest bacterial cells may be more difficult to detect with autofluorescence than previously thought. Ιdentification of bacterial cells even in the FCM (bioLNA population) is challenging, given that the fluorescence level of stained cells at times may be comparable to that seen from abiotic particles. HNA and ABC displayed highest concentration on a humid and warm day after a rain event (4/14), suggesting that both populations correspond to wet-ejected fungal spores. Overall, information from both instruments combined reveals a highly dynamic airborne bioaerosol community over Atlanta, with a considerable presence of fungal spores during humid days, and a bioLNA population dominating bioaerosol community during dry days.


1997 ◽  
Vol 41 (5) ◽  
pp. 324-330 ◽  
Author(s):  
Ana T. López-Navarro ◽  
Angel Gil ◽  
Antonio Sánchez-Pozo

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