Meat Slicer Research Articles

Two Listeria monocytogenes outbreaks in a cancer centre: onsite food premises and their potential health risk to patients

BackgroundThis report describes two L. monocytogenes outbreak investigations that occurred in March and September of 2018 and that linked illness to a food premises located in an Ontario cancer centre. The cancer centre serves patients from across the province.MethodsIn Ontario, local public health agencies follow up with all reported laboratory-confirmed cases of listeriosis to identify possible sources of disease acquisition and to carry out investigations, including at suspected food premises. The Canadian Food Inspection Agency (CFIA) is notified of any Listeria-positive food product collected in relation to a case. The CFIA traces Listeria-positive product through the food distribution system to identify the contamination source and ensure the implicated manufacturing facility implements corrective measures.ResultsOutbreaks one and two each involved three outbreak-confirmed listeriosis cases. All six cases were considered genetically related by whole genome sequencing (WGS). In both outbreaks, outbreak-confirmed cases reported consuming meals at a food premises located in a cancer centre (food premises A) before illness onset. Various open deli meat samples and, in outbreak two, environmental swabs (primarily from the meat slicer) collected from food premises A were genetically related to the outbreak-confirmed cases. Food premises A closed as a result of the investigations.ConclusionsWhen procuring on-site food premises, healthcare facilities and institutions serving individuals with immuno-compromising conditions should consider the potential health risk of foods available to their patient population.

High voltage atmospheric cold plasma technology as a food safety intervention for decontamination of cutting tools during ready-to-eat poultry meat slicing

This study aimed to build a prototype that integrates a cold plasma capability into a manual meat slicer while it is in operation to minimize cross-contamination from the circular cutting blade. A high voltage atmospheric cold plasma (HVACP) generator was attached to a meat slicer with a rotating 22.5-cm diameter stainless steel slicing blade. The meat slicer with the installed cold plasma generator was contained within a sealed, clear acrylic box. Listeria innocua (LI) was selected as the test organism, and initial testing was performed on stainless-steel coupons in room air at a relative humidity ranging from 30 to 90% for treatment times up to 240 s. Results found that 240 s and 90% RH showed a 3.0-log reduction of LI. These conditions were then replicated using “dirty” stainless-steel knife while rotating. The results showed only a 0.5-log LI reduction. The gas was changed from air to MA65 gas blend (65% O2, 30% CO2 and 5% N2) and then a 1.91 log LI reduction was achieved on the “dirty” knife. Industrial relevanceDue to the rapid processing speeds required in the food industry, it is difficult to assure the complete cleanliness of the tools and surfaces used at all times, and then, operations like the cutting /slicing step are still one of the critical points for cross-contamination during meat processing. High voltage atmospheric cold plasma (HVACP) is a practical intervention that has the potential to deliver a continuous, in-situ decontamination of the knife during operation to mitigate the risk of cross-contamination. The developed prototype, as shown in this study, can deliver beneficial results in short treatment time and with minimal inputs of air and electricity, without heating effects, minimizing the use of water, or the use of sanitizers.

A Nosocomial Outbreak of Invasive Listeriosis in An Italian Hospital: Epidemiological and Genomic Features.

Listeria monocytogenes (L. monocytogenes) is a widespread opportunistic pathogen that causes the listeriosis foodborne disease. This bacterium has become a common contaminant of handled food, and a relevant public health issue. Here we describe a nosocomial outbreak of listeriosis caused by an ST451 strain of L. monocytogenes involving three cancer and one immunocompromised patients hospitalized in different units from the same hospital during September and October 2020. The epidemiological investigation was conducted using traditional microbiological methodology combined with a whole genome sequencing approach. The source of contamination was identified in the kitchen hospital, where a meat slicer used to prepare patients’ meals was tested positive to the same sequence type (ST) of L. monocytogenes. This is the first report of an outbreak of listeriosis caused by ST451 in Italy.

Energy Saving for Water Hydraulic Pushing Cylinder in Meat Slicer

Energy Saving for Water Hydraulic Pushing Cylinder in Meat Slicer

The Elimination of Listeria Monocytogenes Attached to Stainless Steel or Aluminum Using Multiple Hurdles.

Ready-to-eat luncheon meats sliced in retail delis have been found to pose the greatest risk of foodborne illness from Listeria monocytogenes among all ready-to-eat foods. Slicers used in delis have many removable parts that are connected with seals and gaskets, with spaces, cracks and crevices that are difficult to clean adequately and may provide a niche for L. monocytogenes survival. Standard cleaning and sanitizing practices used by deli employees may not eliminate Listeria in these niches. Moist heat is known to be more effective against L. monocytogenes than dry heat at the same temperature and time. The study reported here investigated the effects of moist heat combined with quaternary ammonium compounds (5 or 10 ppm), chlorine (10 or 25 ppm) or peracetic acid (10 or 25 ppm) on inactivating L. monocytogenes attached to stainless steel or aluminum coupons cut from commercial deli meat slicer components. All sanitizers when used alone resulted in a 2- to 3-log reduction of L. monocytogenes on stainless steel or aluminum surfaces, while moist heat alone resulted in a 3- to 4-log reduction. When combined with heat the quaternary ammonium was used at 5 ppm, peracetic acid at 10 ppm and chlorine at 10 ppm. When the 2 lethal treatments were combined there was a 5- to7-log reduction as compared to initial inoculation. The results of this study will provide a better understanding and potential methods for the sanitization of industrial deli meat slicers. In turn, the knowledge gained from this study can reduce the risk of contamination and outbreaks of L. monocytogenes and other food-borne pathogens for consumers.

In Memoriam: M. Colin Jordan, MD

M. Colin Jordan, former Infectious Diseases Division Director and Professor of Medicine at both the University of Minnesota and the Oregon Health and Science University (OHSU), died April 8, 2015. Colin lived an exceptional life, touching patients and colleagues with his excellence and high expectations as a physician and scientist and his rare combination of warmth and nurturing with cutting, yet understated, humor. He did not talk much about his past, so few may know he was born in a bomb shelter in England in 1941, came to the United States aboard the Queen Elizabeth at age 6, and was signed by Walt Disney studios as a dancer at the age of 12. Colin was an accomplished college baseball player, and after graduation from Loyola Marymount he was offered a contract with the Los Angeles Angels; however, instead of becoming a baseball player, he decided to go into medicine. After medical school at Creighton, he trained at the University of Washington (UW), where he worked with many outstanding clinicians, including their stellar Infectious Diseases group and Bill Kirby, with whom he wrote one of his first papers. His time at UW helped inspire his career, including his becoming an Epidemic Intelligence Service (EIS) officer from 1970 to 1972. An early indication of both his talent and humor was his publication in the American Journal of Public Health, from an EIS investigation, entitled “Salmonellosis among restaurant patrons: the incisive role of a meat slicer”. After stints as a faculty member at UCLA and Davis, he became Division Chief at the University of Minnesota, serving from 1984 to 1998. At Minnesota, where I had the pleasure of working with him, he developed a strong multi-institution Division into a warm and collegial group. From 1998 to 2005, he served as Chief of ID and the first E.H. Cooley Professor of Medicine at OHSU. A staunch believer that scientifically well trained clinicians can provide important insights and have a major role in research, he made many contributions to the understanding of cytomegalovirus infection including, particularly, its transmissibility through sexual contact, murine models of disease, the biology of latency, resistance to antivirals, and molecular detection for diagnostic and research uses. Everywhere he served or led, he influenced students, other trainees, patients, and peers with not only his critical thinking as a scientist and clinician, but also his decency, fairness and compassion, and his low tolerance for puffery and pretension, the latter remarkable for an accomplished academician and almost as rare then as now. He helped motivate and propel many students and trainees into successful careers as physicians and scientists. As he watched medicine and science becoming a business, rather than the calling and commitment which he advocated for and lived by example, it's impossible to know whether Colin ever dreamed of again standing on a major league baseball field. In any case, to all whose lives he touched, he will always be seen as a Major League physician, scientist, and, most important, friend. He leaves his wife, Pamela Lahrs, his previous spouses, Bonnie Baskin and Patricia Jordan, daughters Teresa and Angela, son Colin Jr., and 4 grandchildren. Many fascinating aspects of his life and work, from that bomb shelter to academia, and of his generous personality are captured in his enjoyable book, “Briefings from a Doctor's Foxhole”. If desired, donations in his honor can be made to OSHU or the charity of your choice.

Lethality of moist heat and silver dihydrogen citrate sanitizer combinations on Listeria spp. adhered to components of a deli meat slicer

Abstract Deli meat slicers have been implicated in cross-contamination of ready-to-eat (RTE) foods with Listeria monocytogenes that has resulted in several listeriosis outbreaks. We investigated the lethality of moist heat and silver dihydrogen citrate (SDC) sanitizer on Listeria species that were inoculated on stainless steel (SS) and cast aluminum (AL) coupons cut from actual components of a deli meat slicer. The coupons inoculated with Listeria species were subjected to treatments inside and outside of meat slicer using a commercial bread proofer that was operated for 7 h at 66 °C. Post treatment recoveries of the inoculated Listeria from the treated coupons were enumerated using MOX growth medium. All treatments produced significant ( P = 0.05) log reductions compared with positive and untreated negative controls. Moist heat reduced the inoculated bacteria to non-detectable levels when the coupons were placed inside the motor compartment of the slicer and the sanitizer plus moist heat gave same results for the coupons placed inside and outside of the slicer. Chemical sanitizer treatment alone showed average log reductions of around 5 CFU/cm 2 on AL and SS coupons respectively and the moist heat alone treatment on both AL and SS coupons showed a log reduction of 4.49 and 4.87 when placed externally and above 6 logs when placed inside the motor compartment. Sanitizer plus moist heat treatments showed highest log reductions of Listeria species to non-detectable levels on deli meat slicer components when placed inside or outside the motor compartment of the slicer. Thus the sanitizer and moist heat combination treatments can effectively reduce the Listeria cells attached onto food contact surfaces of a deli meat slicer.

Turning a Scientific Tool Into an Engineering Machine

Rock Tester Nobody knew where the oil and gas was trapped inside shale until a scanning electron microscope (SEM) showed the pores within the organic material inside. Now there are a growing number of machines creating three-dimensional (3D) digital replicas of these rocks by combining SEM imaging with a focused ion beam (FIBSEM), which cuts off ultra-thin slices like a meat slicer, revealing multiple layers within. These 3D digital images are incredibly detailed, but they are based on cubes whose longest side is 10–20 micrometers—millionths of a meter—making them small enough to fit into the spaces in porous sandstone. When it comes to building reservoir models, it leaves engineers wanting more. “The real challenge is we are creating micron-sized images and dealing with square miles of resources,” said Carl Sondergeld, a professor at the Mewbourne School of Petroleum and Geological Engineering at the University of Oklahoma (OU). “If we can transcend those scales we can do a better job of characterizing reservoirs.” In the pursuit of more, he and Chandra Rai, professor and director of the Mewbourne School, have built up one of the largest unconventional rock research laboratories, backed by 12 oil companies. The focus has been on understanding the workings of the nearly impermeable rocks, which has changed how some properties are measured. The large lab displays Sondergeld’s constant hunt for improved tools for analyzing how rocks and reservoirs perform. The laboratory recently added the latest generation of scanning electron micro-scopes from one of the biggest makers of these instruments, FEI. One thing that sets this FIBSEM machine apart is its ability to stitch together thousands of micron-scale images to create 2D pictures covering rock surfaces measured in millimeters rather than micrometers. These hyper-detailed pictures offer an overview of an area, with the option of zooming in for a closer look to see if low-resolution impressions are correct. They often are not. Another plus is its ability to create images using extremely low power—as low as a 100 V compared with 30,000 V for older machines—creating images that may offer better ways of measuring critical details, such as the amount of kerogen—the organic material that is the source of the oil and gas.

Comparative analysis of training delivery methods for new employees cleaning and sanitizing retail deli slicers: An exploratory study

The objectives of this study were to characterize the performance of new employees receiving four types of training delivery methods and determine which training method was most effective in interpretation and execution as measured by temporal performance, ATP bioluminescence and participant survey. Participants with limited food service experience received one of four types of food safety training delivery methods for cleaning and operating a meat slicer. The food safety training delivery methods included; no instruction, written instruction, demonstrations and written instruction with demonstrations. Participants were then instructed to slice four slices of bologna and then clean the slicer based on the training they received. Temporal performance as measured by time was recorded per participant and adenosine triphosphate bioluminescence (ATP-B) was measured to determine the hygienic condition of the slicer post cleaning. Next, participants were given a survey asking them to list the steps for cleaning a deli slicer in proper order and their perceived cleanliness of the slicer based on the training delivery method. When written instruction and demonstrations was used as a delivery method, temporal performance increased, ATP-B readings were lower and participants perceived it as an effective training method.

Inactivation of Listeria monocytogenes on ready-to-eat food processing equipment by chlorine dioxide gas

The effectiveness of chlorine dioxide (ClO2) gas to control Listeria contamination on food contact and environmental surfaces was investigated in order to comply with the zero tolerance policy. Different ClO2 gas concentrations (0.3, 0.5, 1 and 2 mg/l) were evaluated in order to inactivate Listeria monocytogenes (planktonic cells and biofilms) on stainless steel coupons. An ideal condition was then selected, and its applicability was studied on a commercial meat slicer and an industrial hot-dog peeler (using a surrogate organism). L. monocytogenes biofilm cells initially showed more sensitivity to ClO2 treatments, as compared to planktonic cells, but after 10 min, ∼4 log CFU/cm2 reduction was observed for all the concentrations used. The treatment at 2 mg/l for 30 min was selected for the further validation study. Complete pathogen inactivation, >5 log CFU/cm2, was obtained on both the meat slicer and peeler, demonstrating the potential applicability of ClO2 gas as a sanitizing agent for RTE meat processing equipment.

Occupational transmission of hepatitis C virus resulting from use of the same supermarket meat slicer

Tracing risk factors for acquiring hepatitis C virus (HCV) in an HCV-infected patient, the only identified risk was working at the same butcher's counter of a supermarket as another HCV-infected patient, using a common ham cutting machine, with frequent bleeding hand injuries. A phylogenetic analysis showed a high percentage of nucleotide homology between the two patients’ strains.

Modeling the Surface Cross-Contamination of <i>Salmonella</i> spp. on Ready-to-Eat Meat via Slicing Operation

Salmonella spp. surface transfer patterns/models between ready-to-eat (RTE) deli meat and a typical meat slicer are presented. A five-strain cocktail of Salmonella spp. was inoculated directly onto the rim of a round slicer blade at an initial level of ca. 4, 5, 6, 7 or 8 log CFU/blade (ca. 3, 4, 5, 6 or 7 log CFU/cm2 of the blade edge area). Thereafter, a RTE deli meat (ham) was sliced to a thickness of 1.5 - 2.0 mm. In another cross-contamination scenario, a clean blade was initially used to slice ham, which was pre-surface-inoculated with the Salmonella cocktail (ca. 2, 3, 4, 5, 6 or 7 log CFU/cm2 with a total area of 100 cm2), followed by slicing of an un-inoculated ham. The log CFU of Salmonella per ham slice was determined and empirical models were developed. The models, follow the decreasing Power law, predict the surface cross-contamination of Salmonella spp. (at any initial level) for sliced deli meat (ham) and will provide a useful tool in developing RTE meat risk assessments. Surface transfer patterns of three foodborne pathogens, i.e. Listeria monocytogenes, E. coli O157:H7 and Salmonella predicted by models are also presented.

Modeling Surface Transfer of Listeria monocytogenes on Salami during Slicing

Listeria monocytogenes has been implicated in several listeriosis outbreaks linked to the consump tion of presliced ready-to-eat (RTE) deli meats, which has drawn considerable attention in regard to possible cross-contamination during slicing operation at retail and food service environments. Salami with 15% fat (a moderate l fat content deli item) was used to investigate the transfer of L. monocytogenes between a meat slicer and salami slices and to understand its impact on food safety. A 6-strain cocktail of L. monocytogenes was inoculated onto a slicer blade to an initial level of approximately 3, 5, 6, 7, or 9 log CFU/blade (or approximately 2, 4, 5, 6, or 8 log CFU/cm2 of the blade edge area), and then the salami was sliced to a thickness of 1 to 2 mm (case I). For another cross-contamination scenario, a clean blade was first used to slice salami loaf that was previously surface-inoculated with L. monocytogenes (approximately 3, 5, 6, 7, 8, or 9 log CFU/100 cm2 area), followed by slicing the uninoculated salami loaf (case II). The salami slicing rate was maintained at an average of 3 to 4 slices per minute in all the tests. The results showed that the empirical models developed in this study were reasonably accurate in describing the transfer trend/pattern of L. monocytogenes between the blade and salami slices if the inoculum level was >5 log CFU on the salami or blade. With an initial inoculum at 3 or 4 log CFU, the experimental data seemed to suggest a rather random pattern of bacterial transfer between blade and salami. The currently developed models are microbial load (n), sequential slice index (X), and contamination route dependent, which might limit their applications to certain conditions. However, the models may be further applied to predict the 3 or 4 log CFU level (and below) cross-contamination of salami slicing process. Considering only few data are available in the literature regarding food pathogen surface transfer, the empirical models may provide a useful tool in building risk assessment procedures.

Modeling Transfer ofListeria monocytogenesfrom Slicer to Deli Meat During Mechanical Slicing

Listeria monocytogenes has been implicated in several listeriosis outbreaks linked to the consumption of presliced ready-to-eat (RTE) deli meats. The possible contamination of sliced RTE meats by L. monocytogenes during the slicing process has become a public health concern. The objectives of this study were to investigate the transfer phenomena of L. monocytogenes between a meat slicer and ham slices, and to develop empirical models to describe the transfer during slicing. A six-strain cocktail of L. monocytogenes was inoculated onto a slicer blade to an initial level of approximately 3, 6, or 9 log(10) colony-forming units (CFU)/blade (2, 5, or 8 log CFU/cm(2) of the blade edge area), and then the ham was sliced to a thickness of 1 to 2 mm (Case I). As a second cross-contamination scenario (Case II), a clean blade was used to slice ham previously inoculated with L. monocytogenes (3, 6, or 9 log(10) CFU per meat surface of ca. 100 cm(2)) prior to slicing uninoculated ham. The ham slicing rate was maintained at an average of three to four slices per minute for both Case I and II. Although the overall recovery ratio, including slicer surfaces and collected ham slices, was less than 100%, more ham slices were contaminated with L. monocytogenes when the blade was contaminated with higher initial levels of L. monocytogenes. Empirical models were developed to describe the transfer of L. monocytogenes between blade and ham slices. The models may be applied to predict the number of ham slices that may be contaminated by a L. monocytogenes-contaminated slicer during ham slicing operation. However, the models are both microbial load and contamination route dependent, which might limit their applications to certain conditions. This study showed the initial step for the development of surface transfer model and discussed the factors that might need to be considered and included in future study to expand the model applications.

Method for preparing permanent brain slices and serial slice images for education and MRI correlation

It is important to understand the anatomical structures of the human brain in horizontal planes. Serially sectioned brain slices can easily be made with a meat slicer. The objective of this research was to enhance the educational value of serial brain slices made with a meat slicer through various applications. Two brains were taken out of two cadavers and embedded with gelatin solution to make two brain blocks. The first brain block was serially sectioned at 5 mm thickness using a meat slicer to make 28 horizontal brain slices. Each brain slice was embedded with a synthetic resin mixture to make 28 permanent specimens. The second brain block was magnetic resonance-scanned at 1.4 mm thickness to make 130 horizontal magnetic resonance images, then serially sectioned at the same thickness using the meat slicer to make 130 horizontal brain slices. Each brain slice was scanned into a computer to make a series of slice images. Ten anatomical structures in the slice images were outlined to make segmented images. Corresponding magnetic resonance images, slice images, and segmented images were stacked and volume-reconstructed to make three-dimensional images, which were sectioned and rotated at free angles. We show that the serial brain slices made with a meat slicer can be permanently preserved and used in a variety of educational settings. Anat Rec (Part B: New Anat) 289B:64-71, 2006. (c) 2006 Wiley-Liss, Inc.

Quality of Tomato Slices Freshly Cut from Fruit Treated with Methyl Jasmonate

The objective of this study was to determine if treatment with methyl jasmonate (MJ), a naturally occurring substance, would extend the shelf life of tomato slices, specifically when slices were cut from fruit previously treated with this natural product. Tomatoes were harvested at breaker stage. The fruit were divided into four lots. The first three lots were treated with MJ right after harvest at the breaker stage. Fruit from the first lot were sliced immediately after MJ treatment. Fruit from the second lot were placed at 20 °C and allowed to ripen to red stage before slicing. Fruit from the third lot were treated the same way as those in the second lot except they received an additional MJ treatment just before slicing. Fruit from the fourth lot were placed at 20 °C and allowed to ripen to red stage before MJ treatment and slicing. Each lot also included an untreated control. MJ treatments were carried out in 200-L airtight containers. MJ was spotted onto filter paper at final vapor concentration of 10-5 M. Fruit were cut with a meat slicer to obtain slices with 5-mm thickness. Slices were placed in 1-L clear plastic trays with lids and stored at 5 °C. Samples were transferred daily from 5 to 20 °C for evaluation. Fresh-cut tomatoes treated with MJ and sliced at breaker stage (lot 1) had less decay, better quality, and longer shelf life than the untreated slices. However, no differences were found between the control slices and treated slices at the red stage regardless the time of MJ treatment and whether or not additional MJ treatments were applied (lots 2, 3 & 4). The results indicate that the effectiveness of MJ in reducing decay and maintaining quality is affected by the stages of ripeness of tomatoes and the types of decay.

Effect of comminution method and raw binder system in restructured beef

The effect of particle size, method of particle size reduction (grinding, flaking, slicing) and alginate or Fibrimex ™ binding systems on processing properties of restructured beef were investigated. The size of semimembranosus muscles was reduced with a meat slicer, grinder or flaker (Comitrol) through machine openings that were 2, 4 and 8 mm in size. Bind of meat pieces in raw and cooked beef steakettes were measured. Sensory evaluation to determine the effect of method of size reduction on texture of beef steakettes was done only on steakettes manufactured with alginate. Beef steakettes manufactured with the alginate binding system had significantly ( p < 0.05) higher raw bind values than did the beef steakettes manufactured with Fibrimex. Slicing meat for the manufacture of restructured beef steakettes resulted in a higher raw bind than did either grinding or flaking the meat. Significant ( p < 0.05) interactions were observed for the bind of cooked steakettes between binder and method of size reduction and binder and opening size. When alginates were used to make restructured steakettes the bind of the cooked product was less ( p < 0.05) when meat was sliced than when it was ground or flaked. However, when Fibrimex was used, bind was stronger when sliced meat was used. The alginate system resulted in higher binds for cooked product when particle size was smaller but with the Fibrimex system bind was higher when particle sizes were larger. A consumer panel on alginate restructured steakettes showed no preference for the texture produced by the different methods of particle size reduction.

Adenosine Triphosphate Bioluminescence for Hygiene Monitoring in Health Care Institutions

An investigation was conducted to assess the practical use of an adenosine triphosphate (ATP) bioluminescence assay to evaluate the effectiveness of cleaning and sanitizing meat slicers in eight health care institutions. The ATP bioluminescence assay was compared to conventional swabbing techniques using standard plate count to enumerate microbial load. Assays were performed on meat slicers before use, after slicing a meat product and after sanitizing. There was a general overall agreement in results obtained by both methods but the ATP assay gave a better indication of the cleanliness of the meat slicer as it was able to detect the presence of meat residues left on the blade after improper sanitation. Results were available within 5 min using the ATP bioluminescence method, thus providing an opportunity for immediate remedial action.

Salmonellosis outbreak at a Vermont hospital.

An outbreak of gastrointestinal illness occurred at a hospital in northern Vermont during September 1981. Of the 292 hospital employees surveyed, 43 had diarrheal illness; 12 of them had positive cultures for Salmonella, serotypes chester, tennessee, or habana. In addition, three individuals who were culture-positive but did not have diarrhea were counted among the cases. Illness was related to eating roast beef or cold cuts (P less than .01) in the month of September. One food specimen, an unopened package of precooked roast beef supplied by a New York processor, was found to be contaminated by Salmonella, serotypes chester, tennessee, and livingston. Cold cuts were believed to be secondarily contaminated by a meat slicer. Three of 80 patients whose charts were reviewed had nosocomial diarrhea; two of them had positive cultures for Salmonella, serotype chester. Secondary transmission of Salmonella from hospital staff was the likely source for at least two of the patients.

Investigation on tomographic examinations of the temporal bone. Part II: Cross sectional anatomy of the normal human temporal bones (author's transl)

The study of cross sectional anatomy of the normal human temporal bones was performed by macrosections, Softex radiographs and tomographs.The temporal bones, taken at autopsy, were sectioned tomographically in planes similar to those employed in clinical examination, then they were decalcified, and macrosections in the desired planes were made by cutting 2mm. thick with a commercial meat slicer. Then Softex radiographs of the macrosections were taken with a low intensity x-ray machine.Their comparative study demonstrated that macrosections of the normal middle and inner ear structures were useful for analysis of tomograms, and that Softex radiographs of the macrosections with 2mm of depth could elucidate details of the tomographic sections of the temporal bones.