Dear Colleagues, I have sent this query to other lists, so I apologize for cross posting. Melanins appear to be difficult to quantify given their diversity, ability to complex with other molecules, and lack of solubility. They are also known to interfere with PCR. We are having some problems amplifying bacterial 16s from the buccal cavity of a crustacean that has dark mouthparts and we suspect melanins (or related pigments) have something to do with this (I am aware that some research has challenged the existence of melanins in crustaceans to begin with, but there is a large literature believing they exist). Can anyone recommend a simple method for detection/quantification of melanins? The literature seems to be as diverse as the melanins themselves, with approaches ranging from HPLC and NMR to spectrophotometry and even a gravimetric technique. Yet, many of the simpler techniques were published in the 70s and little follow up has occurred since then (for example, a gravimetric method by Borovansky has only been cited once since 1978 in spite of hundreds of papers on melanins). We lack the resources for doing the more advanced chemical techniques (e.g., HPLC, NMR, ESR, spectroscopy, radiolabeling) so I was wondering if anyone has experience with colorimetric methods such as the one proposed by Das et al. (1978) J. Neurochem.26: 695-699 or any other less expensive alternative. Inquiring minds want to know... Regards, Edwin -- Dr. Edwin Cruz-Rivera Assistant Professor of Marine Biology Department of Biology American University in Cairo AUC Avenue, P.O. Box 74 New Cairo 11835, Egypt
Tel. 20.2.2615.2906 Fax 20.2.2795.7565 Email: [email protected] "It is not the same to hear the devil as to see him coming your way" (Puerto Rican proverb)
