Freezing Tissues for Cryosectioning

Histopathology Tissue Submission Freezing Tissues for Cryosectioning

Freezing Tissues for Cryosectioning

Background
If you're not familiar with preparing tissues for cryosectioning or working with frozen sections, you should read
Cryotechniques for Light Microscopy © Woods and Ellis 2000.

There are many variables affecting the quality of frozen sections. You may have to experiment with different methods. Be advised that it can be difficult to get acceptable sections from some tissues. Fatty tissues are a notable example.

Also be advised that although we routinely use Plus (charged) slides to aid adherence of the section to the slide, one still must take care not to dislodge the sections during staining. Other means of increasing adhesion are available.

Embedding medium and molds
Most frozen tissues we receive are embedded in OCT in cryomolds. [Supplies page] Embedding medium helps conduct heat away from the specimen during freezing, helps protect the tissue from drying during storage, and supports the tissue during sectioning. We suggest placing a drop of OCT in the bottom of the mold and placing the tissue in the OCT. This will hold the tissue in place while you fill the mold with OCT. Just be careful to exclude large bubbles, fill the mold level full, and freeze by one of the methods below.

Label the mold with a lab marker before freezing.

If you want the tissue in a particular orientation, such as a piece of skin or hollow organ on edge, you can chill the filled mold, which will make the OCT thicken and help hold the tissue in place, but try to freeze the tissue as rapidly as possible to minimize freezing artifacts.

We also recommend not trying to embed large pieces of tissue, not more than about 1 cm x 1 cm x 4 mm. Don't crowd the mold with too many pieces of tissue.

Freezing methods
One simple method is to use dry ice (-70C) in block form placed in a styrofoam container. Place the filled cryomold on the block to freeze it. This method has the advantages of simplicity and safety, but does not freeze the tissue as rapidly as immersion in a freezing medium.

The method we prefer uses dry ice in pellet form. Place a small stainless steel bowl (or Pyrex or polypropylene beaker) in the bottom of a styrofoam container and fill the space around the bowl with dry ice pellets. Place some pellets in the bowl and slowly add isopentane (2-methyl butane) or acetone. Work in a fume hood, of course, as these are flammable. When the pellets stop bubbling vigorously, the "slurry" is ready. Once you've filled the mold and oriented the tissue, immerse it in the liquid to freeze it.

Isopentane also can be chilled in liquid nitrogen (-176C). With the liquid nitrogen in a styrofoam container or Dewar flask, use a tongs to lower a stainless steel, Pyrex, or polypropylene container of isopentane into the liquid nitrogen. The isopentane will start to become opaque as it nears freezing. Take the isopentane out of the liquid nitrogen and freeze the specimen as described above. Chill the isopentane again as necessary for subsequent tissues. This method has the advantage of very rapid freezing.

Storage
Frozen tissues can be stored in a -80 freezer. If the tissues were frozen in a flammable freezing medium, take care to allow it to evaporate before placing the blocks in the freezer.

Even if frozen in embedding medium, tissues must be protected from drying, which can ruin them. Tightly wrapped foil envelopes and screw-top plastic centrifuge tubes are commonly used, and it's a good idea to double wrap the specimens or place them in a container within a second container. Best, however, is to section and stain them as soon as possible.

See Cryotechniques for Light Microscopy © Woods and Ellis 2000 for more information.

Additional News and Announcements

  • Research News Digest for Thursday, February 23, 2017

    Posted by Office of the Vice President for Research | 02/23/17
  • IRB Forum: Revised Human Subjects Protocol and Sample Consent Form

    The UAB Office of the IRB will host a forum go over the revisions to the Human Subjects Protocol and Sample Consent Form. This forum will be offered on two occasions:
    • Thursday 3/02/17 from 9am - 10:30am in Finley Conference Center, Kaul Building
    • Monday, 3/06/17 from 1:30pm - 3:00pm in Finley Conference Center, Kaul Building
    The same information will be presented at both forums. Registration is not required.
    Posted by Office of the Institutional Review Board for Human Use | 02/21/17
  • Input from Faculty and Core Users Requested

    The UAB Faculty Senate Research Committee is seeking institution-wide input from UAB faculty and Core users on the best way to achieve our institutional research goals.
     
    Please provide your constructive comments and suggestions below on the UAB Spark website: https://ideas.uab.edu/a/ideas/top/campaigns/19237. You will be required to log in with your blazerid to access the site. If you would like an idea posted anonymously, please contact moderators Karen Gamble at klgamble@uab.edu, Zdenek Hel at zhel@uab.edu or David Chaplin at dchaplin@uab.edu.
    Posted by UAB Faculty Senate | 02/20/17
  • Call for Abstracts for UAB Health Disparities Research Symposium

    The UAB Minority Health & Health Disparities Research Center (MHRC) will host the 12th annual UAB Health Disparities Research Symposium, on May 3, 2017 at the DoubleTree Hotel. This year's symposium will take an in-depth look at the role of social determinants in population health.
     
    The symposium showcases the work being done to reduce health inequities in Alabama, the south, and the U.S. It provides an overview of the latest in health disparities research. Scientists and scholars look to it as an excellent opportunity to share discoveries, new approaches, and successful models.
     
    Abstracts for original health disparities research by investigators, students, and community partners are now being accepted. In addition to the fields of basic science, clinical research, social and behavioral science, community-based and health outcomes research, abstract submissions are encouraged for social determinants of health, behavioral and biological mechanisms of health disparities, community-based approaches to health, health policy, and population health. The deadline for abstracts is Friday, March 3.
     
    Featured speakers include Catarina Kiefe, Phd, MD, the Chair of Department of Quantitative Health Sciences, University of Massachusetts Medical School.
    Dr. Kiefe combines the rigor of mathematics with the needs of clinical medicine. She draws upon the intellectual curiosity and drive for discovery that marked her early career as an abstract researcher, using it to help her lead an applied research program with the objective of improving healthcare outcomes for individuals and populations.
     
    Jeroan Allison, MD, MS is Professor and Vice Chair of the Department of Quantitative Health Sciences at the University of Massachusetts Medical School, where he also serves as Associate Vice Provost for Health Disparities Research. Dr. Allison’s research focuses on quality measurement, implementation science, and statistical methodology, with an emphasis on eliminating racial/ethnic disparities in medical care and health outcomes. 
     
    The 2017 UAB Health Disparities Research Symposium is produced by the UAB Minority Health & Health Disparities Research Center and co-sponsored by two national centers for health disparities research: Mid-South Transdisciplinary Collaborative Center, led by Mona Fouad, MD, MPH Director of Professor, UAB Division of Preventive Medicine and Director of the UAB MHRC, and Gulf States Health Policy Center, led by Regina Benjamin, MD, MBA, Founder and CEO of BayouClinic and 18th U.S. Surgeon General.

    Attachments:
    Posted by Minority Health and Health Disparities Research Center | 02/20/17
  • Research News Digest for Monday, February 20, 2017

    In this edition of the Research News Digest:
    Announcements
    UAB-HudsonAlpha Genomic Medicine Post-Doctoral Training Program
    Input from Faculty and Core Users Requested
    Call for Abstracts for UAB Health Disparities Research Symposium
    Upcoming Events
    CCTS Lunch and Learn
    Genetics and Genomics Seminar Series - Lysosomal Acid Lipase Deficiency (LAL-D): An Underrecognized but Treatable Disorder
    2017 NIH NHLBI PCTC Cardiovascular Tissue Engineering (CVTE) Symposium
    Renal Symposium on Acute Kidney Injury; Cystic Disorders and Therapeutic Intervention
    Funding Opportunities
    REMINDER: 2017 Special Interest Projects (SIPs)
    Weekly Grants and Contracts Awarded Report
    Reports for 2017 (Updated every Tuesday)
    Posted by Office of the Vice President for Research | 02/20/17
  • UAB-HudsonAlpha Genomic Medicine Post-Doctoral Training Program

    The Helflin Center for Genomic Sciences is currently accepting applications for the NHGRI funded UAB-HudsonAlpha Genomic Medicine Post-doctoral training program.  The purpose of this training grant is to recruit postdoctoral trainees from various disciplines and provide mentorship and clinical research training in genomic medicine.  Trainees will receive a monthly stipend, tuition and fees assistance, health insurance and travel funds (at NIH-defined level).
     
    Sponsor: National Human Genome Research Institute
     
    Deadline: April 1st, 2017
     
    To read about eligibility, deadline and to apply please visit https://www.uab.edu/medicine/genetics/t32  
     
    Contact: Shaila Handattu PhD, MBA hande@uab.edu
     
     
    Posted by Heflin Center for Genomic Science | 02/17/17
  • Research News Digest for Thursday, February 16, 2017

    In this edition of the Research News Digest:
    Agency Notifications
    eRA Enhancements - February 14, 2017
    Announcements
    Free Training Sessions for NSF CAREER Awards
    New Effort Reporting LMS Course for the New Year
    Upcoming Events
    Genetics and Genomics Seminar Series - Lysosomal Acid Lipase Deficiency (LAL-D): An Underrecognized but Treatable Disorder
    2017 NIH NHLBI PCTC Cardiovascular Tissue Engineering (CVTE) Symposium
    Renal Symposium on Acute Kidney Injury; Cystic Disorders and Therapeutic Intervention
    UAB Postdoctoral Research Day
    Funding Opportunities
    REMINDER: 2017 Special Interest Projects (SIPs)
    Weekly Grants and Contracts Awarded Report
    Reports for 2017 (Updated every Tuesday)
    Posted by Office of the Vice President for Research | 02/16/17
  • eRA Enhancements - February 14, 2017

    New features and improvements will be released on February 16, 2017, for the Extramural Trainee Reporting and Career Tracking (xTRACT) system.
     
    Features and Updates
    • Text styling of names that are in all-caps.
    • Upload feature for participating faculty members on a Research Training Dataset (RTD).
    • Ability to cite publications with a large number of authors.
    • Year Awarded correctly shown in Table 8 for subsequent grants.
    Post-release details and screenshots will be made available through Online Help for xTRACT resources. The original announcement may be found on the eRA News website.
     
    Posted by Office of Sponsored Programs | 02/14/17
  • New Effort Reporting LMS Course for the New Year

    In conjunction with the implementation of the revised Effort Reporting Policy and Procedures effective October 1, 2016, a new effort reporting training module is now available in the UAB Learning System (LMS) system.
     
    This course is required of all employees who must certify effort on sponsored project(s) (UAB Project Employees, excluding non-exempt/biweekly paid employees) and Departmental Effort Officers (DEOs). Additionally, the school/college dean’s offices may elect to assign this training to other employees that may benefit from the course information as well.  The expectation is this course should be completed prior to certifying effort or distributing effort reports (i.e., before the 3/31/17 end date of the current effort reporting period). For those required to complete this training, the course was automatically assigned in the LMS system in early January 2017.  Those individuals received an email from hs-alerts@healthstream.com with the subject line, “New Assignment in the UAB Learning System”.
    Posted by University Compliance Office | 02/14/17
  • Free Training Sessions for NSF CAREER Awards

    The UAB College of Arts and Sciences is pleased to again offer campus-wide training to junior faculty planning to apply for a National Science Foundation (NSF) CAREER Award. The NSF awards CAREER research grants to new faculty at universities who are at the rank of Assistant Professor (or equivalent) in any of the broad science and social science disciplines that are eligible for NSF grants.  
    Posted by College of Arts and Sciences | 02/14/17
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