From crop improvement and food testing to forensic applications, carcinogenic and toxic nucleic acid stains are something biologists and genome experts have been using for long, notwithstanding concerns over the effects of exposure to these stains. Their basic use is to impart colour to tissues or cells and they also facilitate microscopic study and identification, important for researchers.
In a claim that will change the way researches using these stains are being done, making it completely safe, Indian Institute of Science’s (IISc) J Fathima Benazir says the stain she has developed — tinto rang — is safe even on consumption. Benazir, who had worked extensively on developing this new stain during her doctoral and post-doctoral research at IISc, has launched from her firm Azooka Life Sciences, which is an incubation supported by the institute’s Society for Innovation and Development.
Tinto (crimson red in Portuguese language which the colour of the stain) Rang is an Indian product from the Indian Institute of Science.
Azooka has filed a patent for tingo rang, which is yet to be granted. This stain is safe even on consumption because it is developed from edible plants found in South India. Benazir refused to give the name of the plant considering her pending patent.
Benazir states that the focus of Azooka is to develop safe DNA/RNA fluorescent stains for applications in biological sciences and genomics and tinto tang is safe even on consumption as it is a food additive making it the safest option currently available in the world.
The basic requirement of stains was that the nucleic acid dye has to be fast, sensitive and selective to the nucleic acid so that it can be used in various applications to detect minute quantity of nucleic acids in a biological sample. Explaining why tingo rang is better, she said that the most commonly and widely used stain (ethidium bromide nucleic acid stain) is a potent carcinogenic, mutagenic bio hazard and scientists in a lab deal with carcinogenic and mutagenic strains all the time to run their DNA tests.
Prof H S Savithri of department of biochemistry of IISc claimed, “These stains often alter the structure of the DNA because the interactions with the DNA are very strong. We always felt there was a need for an alternative to the carcinogenic and mutagenic stains available in the market.”
Benazir also said that ethiduim bromide requires at least 10 to 40 minutes to obtain results or visualise DNA but tinto rang stains DNA within a few seconds or at best a minute. According to Alex D Paul, co-founder of Azooka, the fluorescent intensity is seven times greater than the market gel stains.
The DNA can be recovered after visualization and can be used again for multiple tests being a nucleic acid gel stain because the DNA won’t be distorted.