Nucleic acid hybridization natural positions within a chromosome). In 1969, the two scientists published a paper demonstrating that radioactive copies of a ribosomal DNA sequence could be used to detect complementary DNA sequences in the nucleus of a frog egg. Since those original observations, many refinements have increased the versatility and sensitivity of the procedure to the extent that in situ hybridization is now considered an essential tool in cytogenetics. Nucleic acid hybridization In molecular biology, hybridization (or hybridisation) is a phenomenon in which single-stranded deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) molecules anneal to complementary DNA or RNA. Though a double-stranded DNA
Aspergillic acid Aspergillic acid Aspergillic acid is an organic chemical compound with the molecular formula CHNO. It has a pale yellow crystalline appearance. Aspergillic acid is most commonly known as an antibiotic and antifungal agent that is derived from certain strains of the fungus "Aspergillus flavus". In 1940 Edwin C. White and Justina H. Hill discovered that a fungal strain of "Aspergillus flavus" growing in a surface culture on a tryptone-salt was capable of producing a bactericidal filtrate. It has also been shown to be a bactericidal for some Gram-negative as well as Gram-positive bacteria. Over the next few years they worked