Estudo da conservação de material biológico com a tecnologia Fta-card® / Study on the conservation of biological material with Fta-card® technology / Estudio de conservación de material biológico con la tecnología Fta-card®

O Whatman FTA-Card® é um papel-filtro quimicamente tratado, destinado à coleta, transporte, armazenamento de amostras para posterior extração de ácidos nucléicos. A tecnologia FTA-Card® é utilizada para manter estável DNA e RNA em temperatura ambiente, podendo ser utilizados para fixação de uma ampla variedade de material orgânico ou tecidos. Foram realizados testes para certificar sua eficiência na conservação do material a ser analisado com o intuito de eliminar a cadeia fria de conservação, agilizando o processo e diminuindo os custos da execução de exames moleculares associados ao diagnóstico de patologias. Foram testadas oito amostras de felinos na forma de sangue total e soro, para a extração utilizou-se o kit Magazorb RNA Total mini-prep kit (Promega®, EUA), para o diagnóstico foi utilizada a técnica de PCR em tempo real para amplificar o gene CI2 de mamíferos, a fim de visualizar a eficácia na conservação de ácidos nucleicos. A utilização desse método torna possível que o material biológico seja enviado por serviços de transporte postais, reduzindo os custos e viabilizando diagnósticos provenientes de áreas mais remotas.(AU)

Whatman FTA-Card® is a chemically treated filter paper intended for the collection, transport, and storage of samples for later extraction of nucleic acids. FTA-Card® technology is used to keep DNA and RNA stable at room temperature and can be used to fix a wide variety of organic material or tissues. Tests were carried out to certify its efficiency in the conservation of the material to be analyzed in order to eliminate the cold conservation chain, speeding up the process and decreasing the costs of performing molecular tests associated with the diagnosis of pathologies. By using this method, biological material can be sent by postal transport services, reducing costs and making diagnoses from more remote areas feasible. Samples of feline specimens were tested in the form of whole blood and serum, using the Magazorb RNA Total mini-prep kit (Promega®, USA) for the extraction. Diagnosis was performed using real-time PCR technique to amplify the mammalian CI2 gene in order to visualize the effectiveness in conserving nucleic acids.(AU)

Whatman FTA-Card® es un papel de filtro tratado químicamente, destinado a la recogida, transporte, almacenamiento de muestras para su posterior extracción de ácidos nucleicos. La tecnología FTA-Card® se usa para mantener el ADN y el ARN estables a la temperatura ambiente y se puede usar para la fijación de una amplia variedad de materiales o tejidos orgánicos. Se realizaron pruebas para certificar su eficiencia en la conservación del material a analizar con el fin de eliminar la cadena de frío de conservación, agilizando el proceso y reduciendo los costos de realización de pruebas moleculares asociadas al diagnóstico de patologías. Se analizaron ocho muestras felinas en forma de sangre total y suero, para la extracción se utilizó el mini-prep kit Magazorb RNA Total (Promega®, USA), para el diagnóstico se utilizó la técnica de PCR en tiempo real para amplificar el CI2 de mamífero gen, con el fin de visualizar la efectividad en la conservación de ácidos nucleicos. El uso de ese método permite el envío de material biológico por los servicios de transporte postal, lo que reduce los costes y permite realizar diagnósticos desde zonas más remotas.(AU)

Análisis comparativo de las pautas del consejo de organizaciones internacionales de ciencias médicas (CIOMS) 2016: (Parte 2 de 3) / Comparative analysis of the standards of the council of international organizations of medical sciences (CIOMS) 2016. (Part 2 of 3)

Como parte de la evaluación de la asignatura Bioética e Investigación de la Maestría en Bioética, se solicitó a los estudiantes de la VI Cohorte que realizarán un análisis comparativo de las Pautas CIOMS 2016 con documentos anteriores. En esta segunda parte, se presentan las pautas relacionadas con el consentimiento informado, la recolección, almacenamiento y uso de materiales biológicos y datos relacionados, así como la rendición pública de cuentas y la publicación de las investigaciones. Estas pautas son fundamentales para la realización de investigaciones científicas en seres humanos por eso el objetivo de estos trabajos es proporcionar a los investigadores un aporte en su formación y una rápida adaptación a la nueva propuesta CIOMS(AU)

As part of the evaluation of the Bioethics and Research subject of the Master in Bioethics, students of the VI Cohort were asked to make a comparative analysis of the CIOMS 2016 Guidelines with previous documents. In this second part, the guidelines related to informed consent, collection, storage and use of biological materials and related data, as well as public accountability and publication of research are presented. These guidelines are fundamental for carrying out scientific research on human beings, and for this reason the objective of this work is to provide researchers with a contribution in their training and a rapid adaptation to the new CIOMS proposal(AU)

Small-caliber tissue-engineered vascular stent: How to produce a material with physiological remodeling activity / 中国组织工程研究

BACKGROUND: The common clinical treatment methods of cardiovascular disease are vascular reconstruction, including stent interventional therapy, coronary artery bypass grafting and angioplasty. OBJECTIVE: To summarize the latest research progress of tissue-engineered vascular stent materials, such as natural derivative stent materials, synthetic macromolecule materials and composite materials, so as to lay a theoretical foundation for small-caliber vascular transplantation. METHODS: PubMed, WanFang, and CNI databases were retrieved for the articles published from January 2008 to July 2019. The key words were “tissue engineering, biological material, scaffold material, blood vessel” in Chinese and English, respectively. The documents with old content and repeated conclusions were excluded, and 52 eligible articles were enrolled. RESULTS AND CONCLUSION: Autologous vascular grafts, such as saphenous vein and internal thoracic artery, are the best alternatives to small-caliber vessels. However, restenosis of vascular lumen may be induced after transplantation, and the incidence of thrombosis, infection and transplantation failure increases, which seriously hinders the clinical application. Considering these limitations, researchers have embedded tissue-engineered vascular grafts into cells to produce a living material with physiological remodeling activity. This potential solution may bring hope for the future of vascular grafts.

Incidência de acidentes de trabalho com exposição a material biológico em profissionais de saúde no Brasil, 2010­2016 / Incidence of work accidents involving exposure to biological materials among healthcare workers in Brazil, 2010­2016

Introdução: Os acidentes de trabalho com exposição a material biológico (ATEMB) entre os profissionais de saúde ainda são frequentes e podem acarretar consequências à saúde do trabalhador. Objetivo: Descrever as características e as condutas adotadas pós-exposição entre os profissionais de saúde vítimas de ATEMB no Brasil. Métodos: Estudo ecológico, com dados secundários registrados no Sistema de Informação de Agravos de Notificação (SINAN), no período de 2010 a 2016. Realizou-se uma análise descritiva, calcularam-se os coeficientes de incidência (CI) por 1.000/profissionais-ano. Utilizou-se o Stata 14.0 para análise dos dados. Resultados: O maior CI no país foi observado no ano de 2014 (16,84). Na análise por unidade federativa (UF), os maiores CI foram encontrados em Goiás, Minas Gerais, São Paulo e Paraná. Entre os casos notificados, prevaleceram a população feminina, na faixa etária entre 25­31 anos, com 12 anos ou mais de escolaridade, e auxiliares e técnicos de enfermagem (64,71%). O sangue foi o material biológico mais envolvido nos acidentes (74,93%) por meio da via percutânea (75,33%), com a agulha sendo o principal agente causador (57,59%), e 29,71% dos pesquisados não utilizavam luvas no momento do acidente. Nas condutas adotadas pós-exposição, 1,12% recusou a quimioprofilaxia indicada. Entre as variáveis relacionadas em estudo, existiam muitos dados registrados como ignorado ou em branco. Conclusão: A descrição levantada denota a necessidade de medidas de prevenção efetivas que estejam baseadas principalmente no uso do equipamento de proteção individual e na educação permanente e continuada dos profissionais, assim como no preenchimento adequado das fichas de notificação.

Background: Work accidents involving exposure to biological materials (WAEMB) are frequent among healthcare workers (HCW) and might have consequences for their health. Objective: To describe the characteristics of WAEMB involving HCW and post-exposure measures in Brazil as a whole. Methods: Ecological study based on secondary data recorded by System of Information on Notifiable Diseases (SINAN) for the period from 2010 to 2016. We performed descriptive analysis and calculated incidence coefficients (IC) per 1,000 HCW/year using software Stata 14.0. Results: The highest IC corresponded to 2014 (16.84). On analysis per state, the highest IC corresponded to Goiás, Minas Gerais, São Paulo and Paraná. Most victims were women, nursing assistants or technicians (64.71%), workers aged 15-31 years old, and with ≥12 years of formal education. Most accidents involved blood (74.93%) and percutaneous exposure (75.33%); needles were the most frequent causative agent (57.59%). About 29.71% of victims did not wear gloves at the time of the accident, and 1.12% refused chemoprophylaxis. Data missed for several variables of interest. Conclusion: Our description points to the need for effective preventive measures mainly based on use of personal protective equipment, lifelong learning and continuing education for HCW and adequate WAEMB reporting

Adesão aos equipamentos de proteção individual entre trabalhadores de saúde que sofreram acidentes com material biológico / Adherence to standard precautions among health care workers exposed to accidents with biological material

Objetive:To analyze the adhesion to Individual Protection Equipment among health workers who have suffered accidents with biological material. Method:This is a retrospective, quantitative epidemiological study carried out in a hospital of medium complexity between October 2010 and December 2013. Results:The inadequacy of the use of the Individual Protection Equipment during the procedure was more prevalent in people aged up to 29 years-old and inprofessionals of the nursing team. Misuse of equipment was also more prevalent among people who suffered accidents during invasive and bloody procedures. Conclusion:The low adherence or inadequacy of the use of Personal Protective Equipment has been observed and can be linked to both individual and related aspects of employers' institutions.

Objetivo: Analisar a adesão aos Equipamentos de Proteção Individual entre trabalhadores de saúde que sofreram acidentes com material biológico. Método: Trata-se de um estudo epidemiológico, retrospectivo, quantitativo, realizado em um hospital de média complexidade, no período de outubro de 2010 a dezembro de 2013. Resultados: A inadequação do uso dos Equipamentos de Proteção Individual durante a realização do procedimento foi mais prevalente em pessoas com idade até 29 anos e em profissionais da equipe de enfermagem. O uso incorreto dos equipamentos também foi mais prevalente entre as pessoas que sofreram acidentes durante os procedimentos invasivos e com sangue. Conclusão: A baixa adesão ou a inadequação na utilização dos Equipamentos de Proteção Individual foi observada e pode estar vinculada tanto a aspectos individuais como a relacionados as instituições empregadoras.

IRB review points for studies utilizing paraffin blocks archived in the pathology laboratory / 영남의대학술지

In the personalized medicine era, utilizing paraffin blocks in pathology archives for investigating human diseases has come into the limelight. This archived material with clinical data will reduce the research time and could prevent new patient recruitment to obtain tissue for research. However, the clause indicating the necessity of consent from human material providers in the Korean Bioethics and Safety Act has made the Institutional Review Board (IRB) deny permission to use paraffin blocks for research without consent, and alternatively to get the same before starting an experiment. Written consent may be waived off in studies using paraffin blocks with anonymous status or conditions not linked to personal information by applying the paragraph 3, article 16 of the current Bioethics and Safety Act. Also, the IRB should recommend researchers to preserve the blocks as medical records of patients in long-term archives.

Experimental study on long-term outcome of porcine collagen membrane xenotransplantation in vivo / 中国修复重建外科杂志

Methods: Twenty Sprague Dawley rats were randomly divided into 2 groups ( n=10). DermalGen were implanted subcutaneously into the dorsum of rats in experimental group, and the rats in control group were treated with sham-operation. At 3, 7, and 15 days and 1, 3, 6, and 12 months after operation, the samples of experimental group were harvested and gross observation, histological observation, CD31 immunohistochemical staining, and transmission electron microscope observation were taken to observe the inflammatory reaction, angiogenesis, and collagen arrangement. The skin tissues of the control group at 12 months were observed and compared.

Improvement of instrument for preparation of medical patch material / 医疗卫生装备

Objective To modify the existing preparation instrument for medical patch material to realize its scale and automatic production.Methods The instrument had its shaking table improved and a cylindrical processing system added with comprehensive analysis on raw materials and kinds of process flows.A spreading and fixation mechanism for animal materials was placed in the cylindrical processing system,which had the holes for liquid inlet and outlet respectively on its top and bottom.The cylindrical processing system was fixed to the base of the shaking table.Results The instrument enhanced preparation efficiency significantly,and had the raw material utilization rate increased by 20％,product qualification rate raised by 35％,preparation cycle reduced by 33％ and total cost saved by 40％.Conclusion The instrument behaves well in adaptability to multi animals,preparation process,inter-assay difference,raw material utilization rate,product qualification rate and cost reduction,which is of great significance to promote the clinical application of medical biological patch.

Acidente com material biológico: uma abordagem a partir da análise das atividades de trabalho / Accidents with biological material: an approach based on the analysis of work activities

Trata-se de estudo qualitativo feito em hospital universitário, cujo objetivo foi analisar o trabalho de auxiliares e técnicos de enfermagem, categoria mais numerosa entre os profissionais de saúde e mais sujeita à incidência de acidentes de trabalho. Este hospital conta com um pouco mais de 2.000 profissionais de enfermagem. Foram utilizados dois métodos de análise. 1) A Análise Coletiva do Trabalho (ACT), que consiste em reuniões com pequenos grupos de trabalhadores explicando seu trabalho. Foram realizadas quatro reuniões, com 34 participantes, quase todos do sexo feminino; 2) O Modelo de Análise e Prevenção de Acidentes (MAPA), que foi utilizado para compreender um acidente ocorrido em uma das clínicas do hospital, com um acidentado que aceitou participar do estudo. Os resultados revelaram que as rotinas de trabalho caracterizam-se por rol de tarefas de cuidados aos pacientes, marcado por grande variabilidade no cotidiano de suas atividades constantemente interrompidas com sobreposição de tarefas decorrentes de demandas urgentes, além de problemas em aspectos organizacionais na situação que originou o acidente, bem como, a fragilidade do sistema de gestão de segurança do trabalho no hospital.

Abstract The present qualitative study was carried out in a university hospital, with the purpose of analyzing the work of nursing assistants and technicians, the most numerous category among health professionals and more prone to accidents in the workplace. This hospital has little more than 2.000 nurses. Two methods of analysis were used. 1) The Collective Analysis of Work (ACT - Análise Coletiva do Trabalho), consists of meetings with small groups of workers who explain their work. Four meetings were scheduled, and 34 participants, almost all of them females, attended. 2) The Model for Analysis and Prevention of Accidents (MAPA), a unique method for the occupational accidents analysis was held in one of the hospital clinics, with an injured worker that agreed to participate. The results revealed that work routines consist of a list of patients care tasks, characterized by a great variability in their daily work schedule. Many interruptions and overlapping tasks arise from urgent demands, besides issues in the organizational aspects of the situation that engendered the accident, as well as the fragility of the system of work safety in the hospital.

Immobilized Biofilm in Thermophilic Biohydrogen Production using Synthetic versus Biological Materials

Biohydrogen production was studied from the vermicelli processing wastewater using synthetic and biological materials as immobilizing substrate employing a mixed culture in a batch reactor operated at the initial pH 6.0 and thermophilic condition (55 ± 1ºC). Maximum cumulative hydrogen production (1,210 mL H2/L wastewater) was observed at 5% (v/v) addition of ring-shaped synthetic material, which was the ring-shaped hydrophobic acrylic. Regarding 5% (v/v) addition of synthetic and biological materials, the maximum cumulative hydrogen production using immobilizing synthetic material of ball-shaped hydrophobic polyethylene (HBPE) (1,256.5 mL H2/L wastewater) was a two-fold increase of cumulative hydrogen production when compared to its production using immobilizing biological material of rope-shaped hydrophilic ramie (609.8 mL H2/L wastewater). SEM observation of immobilized biofilm on a ball-shaped HBPE or a rope-shaped hydrophilic ramie was the rod shape and gathered into group.

Preparation of calcium titanate coating on titanium and its biosafety / 医学研究生学报

requirement of medical materials for hemolysis experiment (<5%) .MTT assay showed that , after 4 days of culture , the optical densi-ties were 0.498 ±0.218 and 0.566 ±0.266 in the 120℃12 h and 24 h groups and 0.668 ±0.268 and 0.769 ±0.213 in the 150℃12 h and 24 h groups, while after 8 days, the optical densities were 0.767 ±0.267 and 0.836 ±0.236 in the 120℃12 h and 24 h groups and 0.765 ±0.265 and 0.903 ±0.303 in the 150℃12 h and 24 h groups, all significantly higher than in the non-CaTiO3 group at 4 (0.341 ±0.143) and 8 days (0.731 ±0.121) (P<0.05). Conclusion The CaTiO3 coating on titanium is neither mutagenic nor hemolytic and has no toxicity on osteoblasts .Instead, it can promote the proliferation of osteoblasts , and therefore is a valuable coating material for implants .

Application of chitosan and its derivatives in nerve tissue engineering / 中华实验眼科杂志

Chitosan (CS) is known as a polysaccharide with positive charge and good biocompatibility.Researches showed that CS possesses the advantages of nontoxicity,biodegradability,plasticity and good biocompatibility,and therefore it can be used to repair of neural injury and serve as a biological carrier scaffold in engineered nerve tissue.Recently,the research is performed for the modification of CS structure or mix the CS with different materials to prepare the multiple compound and biological vector to offer three-dimensional scaffold and environment for the reconstruction of defective neural tissue and culture of neural stem cells.In addition,CS engineered biological materials are confirmed to possess the better performance,more diverse functions and more dominant effect on the regeneration of neural tissue,so it is predicted a more extensive application prospect in neural repair and regeneration.The basic properties and biological functions of CS,and its application in neural tissue engineering are reviewed.

Análise dos acidentes com material biológico em hospital universitário: uma abordagem a partir da análise das atividades de trabalho / Analysis of accidents with biological material in a university hospital an approach based on the analysis of work activities

Este estudo teve por objetivo compreender, a partir da análise das atividades de trabalho, os aspectos que estão presentes nas origens dos acidentes de trabalho com material biológico que ocorrem com os profissionais de saúde em hospital universitário. Foi realizado no Instituto Central de um grande complexo hospitalar, que conta com um efetivo de enfermagem de pouco mais 2.000 profissionais. Foram utilizados dois métodos. Um, a Análise Coletiva do Trabalho ACT, método pelo qual os trabalhadores são levados a falar como realizam seu trabalho em reuniões de grupos. O outro, o Modelo de Análise e Prevenção de Acidentes de Trabalho M.A.P.A., que consiste na análise em profundidade de acidentes de trabalho, no qual se faz entrevistas e observação buscando compreender os antecedentes causais e distais situados na origem das ocorrências de acidentes. As constatações da ACT revelaram a característica dinâmica do trabalho e suas variabilidades. Evidenciando que para dar conta de todas as tarefas e atividades há uma alta exigência de tempo, que o trabalho exige uma constante vigilância/atenção dos AE/TE para com os detalhes, que mobiliários e equipamentos são antigos e carecedores de manutenção, a pouca valorização do pessoal de enfermagem, que o trabalho sofre interrupções constantes, efetivo trabalhando no limite mínimo. Com o MAPA foram revelados aspectos de sobrecarga de trabalho, realização de procedimentos em ritmo acelerado, falta de desenho ou planejamento da gestão de segurança que considere as peculiaridades e variabilidades das situações de trabalho, bem como falha no cumprimento de Normas Regulamentadoras do Mte.

This study aimed to understand, from the analysis of work activities, the aspects that are present in the origins of accidents with biological material that occur with health professionals in a university hospital. It was held at the Central Institute of a large hospital complex, which has a staff of little more than 2,000 nursing professionals. Two methods were used. One of them , Analysis Collective Labor ACT method by which workers are brought to say the way they perform their work in a group meeting. The other one, the Model Analysis and Prevention of Accidents M.A.P.A, which consists of in depth analysis of accidents in which one does interviews and observation in order to understand the causal antecedents and distal located at the origin of the occurrences of accidents. The findings of the ACT revealed the dynamic nature of work and its variability. Showing that to meet all the tasks and activities there is a high requirement of time, the job requires constant vigilance and attention of the nursing technicians for the details, the furniture and equipment are old and they need maintenance, the devaluation of nursing staff, the duty suffers constant interruptions, professionals working in the limit. The M.A.P.A revealed aspects of overload labor, perform procedures at a fast pace, lack of design or planning of security management that considers the peculiarities and variability of work situations, as well as failure to comply with the Regulatory Standards of MTE.

A normativa do Hospital de Clínicas de Porto Alegre para o armazenamento e utilização de materiais biológicos humanos e informações associadas em pesquisa: uma proposta interdisciplinar / The Hospital de Clínicas de Porto Alegre normative for the storage and use of human biological materials and their associated information in research: an interdisciplinary approach

Este artigo apresenta a justificativa e o processo de elaboração do marco normativo do Hospital de Clínicas de Porto Alegre (HCPA) para o armazenamento e utilização de materiais biológicos humanos e suas informações associadas em atividades de pesquisa. Um grupo de trabalho multiprofissional se reuniu e discutiu todos os aspectos referentes a esta questão que envolve as atividades de biobanco e de biorrepositórios. Como produto deste trabalho é apresentada a Normativa Institucional.

This article presents the rationale and framework for developing the Hospital de Clinicas de Porto Alegre (HCPA) normative for storage and use of human biological material and their associated information on research activities. A multidisciplinary task force was established and all issues related to biobanks and biorepositories activities in periodic meetings were discussed; the final result is presented as an Institutional Normative.

Comments on "Legal and Ethical Consideration in the Use of Human Biological Material" by Youngjoon Ryu et al. in 'The Korean Journal of Pathology, 2010; 44: 111-6'

No abstract available.

Hepatite C em profissionais da saúde: risco de exposição e infecção / Hepatitis C in healthcare workers: risk of exposure and infection

Este artigo de revisão discute aspectos da hepatite C em profissionais da saúde e seu risco de exposição e infecção. Foram abordados temas como associação entre patógenos veiculados ao sangue e profissionais da saúde, hepatite C (epidemiologia, diagnóstico e prevenção), comunicação e registro de acidentes do trabalho com material biológico (sangue e fluidos corpóreos), e relação entre extensão e conseqüências dos acidentes com objetos perfurocortantes e exposição mucocutânea e a hepatite C.

This review article discusses aspects of hepatitis C in healthcare workers and its risk of exposure and infection. Association between bloodborne pathogens and healthcare workers, hepatitis C (epidemiology, diagnosis, and prevention), communication and record of occupational injuries with biological material (blood and body fluids), and relationship between extension and consequences of accidents with cut and puncture objects and mucocutaneous exposure and the hepatitis C were described.

Several Methods for Determination of Lead in Environmental Samples and Biological Materials / 环境与健康杂志

Abstract: The principles, detection limits, advantages, shortcomings and precautions for procedure of spectrophotometry, atomic absorption spectrometry, potential stripping analysis and osillo-polarography for determination of lead in environmental samples and biological materials were introduced in this paper to provide some reference data for the selecting suitable method for determination of lead based on the various kinds of samples, the samples sizes and the various conditions of analytical instruments and equipments.

Avaliação do biiodeto de mercúrio como preservativo de material biológico / Evaluation of mercury bi-iodide as preservative of biological samples

Foi feita uma avaliação do biiodeto de mercúrio (HgI 2 ) como preservativo de material biológico, tendo em vista a sua capacidade de conservação por longo tempo, e a propriedade de não aglutinar partículas. Ao sedimento obtido de 400 amostras de fezes acrescentou-se o iodo-mercurato de potássio a 0,20/0, preparado com formol, álcool e soluto fisiológico, na proporção de três partes de conservante para uma parte de sedimento. Numa segunda etapa empregou-se o conservante a 0,1%, preparado com benzeno, álcool, e soluto fisiológico isotônico. Como controles utilizaram-se os conservantes de Railliet & Henry, o MIF (mertiolato, iodo e formol) e o de Schaudinn. Os resultados avaliados após seis meses revelaram que o iodo-mercurato de potássio a 0,2% (primeira fórmula) preservou adequadamente cistos e trofozoítos de protozoários, além de ovos e exemplares adultos de helmintos, com exceção dos ovos de Humenolepis nana e Hymenolepis diminuta, que se apresentaram mais bem conservados usando a segunda fórmula. Resultados semelhantes obtiveram-se com os controles, evidenciando-se o iodo-mercurato de potássio pela propriedade de não aglutinar as partículas de fezes (AU).

METHODS OF FLUORIMETRIC DETERMINATION OF TRACE AMOUNT OF SELENIUM IN BIOLOGICAL MATERIALS,WATER AND SOIL 1.DETERMINATION OF SELENIUM IN HAIR,BLOOD AND URINE / 营养学报

A modification of Watkinson's method was used for the flaorimetric determination of selenium in blood, hair, urine and animal tissues with 2,3-Di-aminonaphthalene. A mixture of sulphuric, perchloric acid and sodium molybdate was used for digestion. As little as 3 ng selenium in the sample could be estimated out. Coefficients of variation and recoveries for blood, hair, urine and animal tissues were 3.9, 5.5, 3.3 and 5.6%, and 97.0, 95.0, 97.8 and 99.8% respectively. No significant difference in selenium content estimated was found as graded amounts of samples were taken for analysis, indicating no foreign interference in the extracts. Both precision and accuracy of this method are satisfactory.