ARTICLE Revista Brasileira de Ornitologia, 21(2), 120-123 June 2013 INTRODUCTION Te most recent survey published by the Brazilian Ornithological Records Committee in 2011 (CBRO 2011) has shown that Brazil is home to 1,832 bird species, representing one of the richest avifauna of the world. Both cytogenetic analysis and molecular biology have contributed to the identifcation of cryptic species, comprehension of the evolutionary mechanisms among diferent groups, establishment of the taxonomic relations among diferent taxa, sex identifcation for reproduction of birds in captivity, and studies about sex ratios in wild populations. Te description of the short-term culture technique of feather pulp by Sandness (1954) enabled the study of rare wild living birds or birds from zoos representing the less invasive sampling which provides the best results for the study of avian karyotypes (Christidis 1989). Such cells, after properly cultured, can persist in fxative at -20 o C for a long time, resulting in good quality metaphases when defrosted (Christidis 1989, Coleman & Tsongalis 1997). Tere are several non-destructive and non-invasive methods of tissue sampling that can also be used for molecular genetic analysis of birds, such as: blood samples (Haig et al. 1997, Paterson & Snyder 1999, Bouzat 2001), feather pulp (Marsden & May 1984, Viala et al. 2006), fresh adult feathers (Bello et al. 2001, Viala et al. 2006), feces (Robertson et al. 1999), urine (Nota & Takenaka 1999), and egg shells (Chilton & Sorenson 2007). When working with birds, it becomes a priority to adopt less invasive sampling procedures, reducing the amount of physical restraint and the associated dangerousness generated by stress. It is also recommended to optimize the use of remnant tissues collected for further analyses, especially in the case of endangered species (Gaunt & Oring 1999). In human beings with Down syndrome, the DNA extracted from bone marrow cells and lymphocytes of peripheral blood cultures, kept frozen for four years after cytogenetic analysis, allowed the execution of other important genetic evaluations on those patients (Amorim et al. 2007). Our objective was to verify if the cells obtained for cytogenetic analysis from young feather pulps of six Psittaciformes species and stored in fxative solution at -20 o C for up to nine years could be used to extract good quality DNA for molecular studies. We also compared the phenol/ chlorophorm and cell lysis methods for obtaining DNA to determine the most suitable technique for reusing the samples in other research projects, avoiding recaptures. Fixed cytogenetic cells suspension: an alternative for obtaining DNA of birds Denise Monnerat Nogueira 1,3 and Andréa de Andrade Rangel de Freitas 2 1 Departamento de Genética, Instituto de Biologia Universidade Federal Rural do Rio de Janeiro (UFRRJ), Rodovia BR 465 - Km 07, CEP 23890- 000, Seropédica, RJ, Brazil. E-mail: denisemn@ufrrj.br 2 Graduação em Medicina Veterinária, Universidade Federal Fluminense (UFF), Rua Vital Brazil Filho 64, Niterói, CEP 24230-340, RJ, Brazil. 3 Author for correspondence. Received on 16 July 2012. Accepted on 16 March 2013. ABSTRACT: Fixed cytogenetic cells suspension: an alternative for obtaining DNA of birds. Birds are especially sensitive to biological sampling and the stress related to this procedure can infuence important clinical parameters and even threaten the life of the animal. In genetic studies preference has been given to less invasive sampling to obtain DNA. Good quality and quantity of genomic DNA are crucial steps for successful amplifcation by the polymerase chain reaction (PCR) and, therefore, for research and diagnostic purposes. Here, we extracted DNA from small volumes of cell suspension fxed and frozen for up to nine years, previously used for cytogenetic analysis of diferent Psittaciformes species. We compared two protocols of DNA extraction (Cell lysis and Phenol/chloroform). Only the phenol/chloroform method provided adequate DNA for PCR amplifcation, providing suitable DNA for molecular sexing, suggesting that it can also be used for other genetic analyses and avoiding recapture to collect tissue samples. KEY-WORDS: CHD gene; Molecular sexing; Psittacidae, Psittaciformes, feather pulp