Tissue collection

Histopathology testing is a terminal procedure, and, therefore, sampling of any single animal is a one-time event (except in the case of a tissue collected by biopsy). Because it is a regulatory requirement that the tissues from a basic number of... 

Experimental samples are mainly derived from tissue culture cells, laboratory animals, or human tissues collected from hospitals after surgical biopsies and autopsies. With human and animal tissue specimens, it is important to arrest metabolic processes within 5-10 min of collection in order to preserve mRNAs from degradation by internal enzymatic reactions (26,27). Most hospitals use 10% buffered formalin as a tissue fixative. Subsequently, each tissue slice is trapped in a paraffin block. Series of 4-5-pm-thick sections are cut and mounted on silanated slides. Formalin-fixed archival tissues have been successfully used in in situ PCR and in situ hybridization protocols (28-32). However, the procedure for RNA protection is not always followed. It is often difficult to alter or control the routine procedures of hospitals for the required protection of mRNAs in surgically removed human tissues. 

Dissection should be carried out as quickly as possible from tissue collection. If you estimate that more than 2 h are required, keep the tissues at 4°C. 

NOAA. 1987. A summary of selected data on chemical contaminants in tissues collected during 1984, 1985, and 1986. NOAA Tech. Memorandum NOS OMA38. Rockville, MD National Oceanic Atmospheric Administration. 

A Michigan daily farmer, who had a history of health complaints after 1976, developed malignant cancer of the esophageal and stomach wall in 1986 the man subsequently died in 1988 (Sherman 1991). Samples of adipose tissue, collected in 1976 and 1987, revealed PBB concentrations of 0.83 and 0.85 ppm, respectively. Also detected in the fat tissue collected in 1987 were polychlorinated biphenyl (PCB) at 3.57 ppm and chlordane residues at concentrations ranging from 0.018 to 0.039 ppm. 

Since over 60% of all antibiotics used in Japan for veterinary purposes are tetracyclines (35), targeted surveys of tetracycline residues in animal tissues have become of particular importance for public health agencies in Japan (36, 37). In 1991, a limited survey in the Aichi prefecture of residual tetracyclines in tissues collected from 64 cattle and 68 hogs of 1358 slaughtered animals that did not pass inspection at slaughterhouses due to presence of disease symptoms was conducted (38). Among 271 kidney, liver, and other organ samples, 49 (18.1%) were positive to oxytetracycline, 5 (1.8%) to chlortetracycline, and 5 (1.8%) to doxycycline, respectively. One cattle kidney sample was positive to both oxytetracycline and doxycycline, whereas tetracycline was not detected in any of the samples. 

Reference values indicate the upper margin of the current background exposure of the general population and [are used] to identify subjects with an increased level of exposure (Jakubowski and Trzcinka-Ochocka 2005) compared with the background population level. Those values are derived from data on blood, urine, and other tissues collected from population studies (Ewers et al. 1999). Reference values may be derived differently for susceptible groups if physiologic differences are substantial (for example, children vs adults) (Ewers et al. 1999). 

Choi, J.W., Miyabara, Y., Hashimoto, S., Morita, M., 2002. Comparison of PCDD/F and coplanar PCB concentrations in Japanese human adipose tissue collected in 1970-1971, 1994-1996, and 2000. Chemosphere 47, 591-597. 

In an interesting work in Farah, Mathura District, India, Dua et al. (1998) collected the skin lipids from face and blood from the occupationally exposed and unexposed volunteers and found that the levels of both HCHs and DDTs were higher in the samples obtained from the exposed group. They have also found an increase in the levels of both the compounds in Delhi population when compared with the data reported in previous publications on the concentrations in the adipose tissue collected a decade before in Delhi (Ramachandran et al., 1984) and several other parts of India (Kaphalia and Seth, 1983), reflecting the intensive use of these pesticides for malaria control in the sampling area. 

Mori, Y., Kikuta, M., Okinaga, E., Okura, T., 1983. Levels of PCBs and organochlorine pesticides in human adipose tissue collected in Ethime prefecture. Bull. Environ. Contam. Toxicol. 30, 74-79. 

Terminal Blood Collection and Tissue Collection for Histology... 

Before beginning the terminal collection procedures have all serum separation tubes for blood collection labeled and all tubes for tissue collection labeled and filled with 5-10 ml 10% formalin (3.7% formaldehyde). Organs from the same mouse can be pooled in the same tube as they can simply be embedded in a single block for histological analysis. 

Cai Z, Giblin DE, Ramanujam VMS, et al. 1994. Mass profile monitoring in trace analysis Identification of polychlorodibenzothiophenes in crab tissue collected from the Newark/Raritan Bay system. Environ Sci Technol 28(8) 1535-1538. 

Experimental infections, tissue collection, extraction conditions, purification procedures, and strategies for determining the primary structure of the natural bioactive peptides should be adapted to the animal model (size, rarity, possibility to conduct molecular biology investigations, availability of EST, and genomic databases, etc.) considered and to the complexity of the bioactive peptide. 

For tissue collection, take samples according to the method of analysis snap-freeze portions of kidney in liquid nitrogen for RNA extraction, roll tissue in Tissue Tek OCT (Cryoform, IEC, Needham, MA) and snap freeze in isopentane cooled over dry ice fix tissue in 4% paraformaldehyde for in situ hybridization or in 10% buffered formalin for routine histology. 

As mentioned earlier, the purpose of this review is not to detail the actual methods used for tissue cross-reactivity studies but rather to highlight the many important factors that must be taken under consideration during the conduct, evaluation, and regulatory review and of the study. Specific details for tissue collection, generation of control materials, and staining procedures themselves are readily available in the literature. 

Tissue banks are the most common source of human tissues. While surgical biopsy accessions are preferred, they are limited in availability and often unavailable for many tissues (e.g., brain and other vital organs). Therefore the majority of tissue samples used in cross-reactivity studies are those acquired at autopsy. For autopsy accessions all efforts must be made to minimize the time interval between death and tissue collection. Information provided with specimens generally includes age, gender, and usually race and some clinical history and/or cause of death. As suggested in the Points-to-Consider document, the tissues used in a standard tissue cross-reactivity study are acquired from adults (>18 years of age). Pediatric tissues are often very difficult to obtain and are usually not used in a standard tissue cross-reactivity study unless there is a clear pediatric indication for the test article. 

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