Use a sharp blade such as this one, which has a handle with replaceable blades. Handles and blades are available from vendors of histology and pathology supplies.Tissues must be trimmed to a thickness that will allow them to be completely permeated with paraffin, and to provide the orientation needed. We suggest "thick as a nickel" as a thumb rule. Some mouse organs are small enough that they are best embedded whole.
If there is an area of particular interest, such as a tumor, in the specimen, trim the tissue so that the area of interest is near one surface of the specimen, and place that surface down in the cassette.Be sure to let the histotechs know if the area of interest is very small to ensure that it is not lost or missed. Be advised that it is very difficult to trim and embed tissues so precisely that it can be determined before sectioning which sections will contain such areas. In such cases it is advisable to request serial sectioning and to save all sections until you're certain you've obtained the information you need. Blocks can always be cut deeper, but discarded sections are gone forever.Don't place too many tissues in the cassette. Overcrowding can inhibit proper processing, and it isn't possible to get that many tissues positioned in the block for good sectioning anyway. This one should have about 1/2 or 2/3 of the amount of tissue shown. As a general rule, place tissues of similar consistency together. For example, don't place tough tissues such as skin in the same cassette as soft tissues such as spleen or brain. If the tissues vary greatly in consistency, they may not all section well.If the tissue is very small, biopsy pads can be used to help prevent the specimen from being lost. Biopsy cassettes with fine screens also are available. Biopsy pads also can be used to prevent samples of skin and hollow organs from curling during fixation, but care must be taken not to compress or distort the tissue.In general, biopsy pads should not be used with larger tissue samples. However, they can be used to maintain orientation or positioning of trimmed samples, as distortion is of less concern with fixed solid tissues. (See the examples on the Special processing & embedding page.)
The Agency for Healthcare Research and Quality have announced a policy affecting the acceptance of Multiple Program Director(s)/Principal Investigator(s) in appropriate research grant applications. This policy is effective with new applications submitted on or after October 1, 2016.
Topics discussed within the policy announcement include:
Please review the original policy notice here (NOT-HS-16-018) for more details.
All National Science Foundation (NSF) systems, including the NSF website, Research.gov and FastLane, will be unavailable from 5:00 PM on Saturday, September 17, until 4:00 PM on Sunday, September 18. This downtime is scheduled to coincide with repairs to the Foundation's electrical systems. Affected deadlines that fall on Monday, September 19, are extended to Tuesday, September 20, submitter's local time. See the attached NSF downtime notice for more information on affected solicitations.
Effective September 8, 2016, Signing Officials have the ability to electronically request the withdrawal of an application through eRA Commons. A Signing Official has two business days after successfully submitting an error-free application to reject the application. If more than two business days have elapsed, the Signing Official must contact the Division of Receipt and Referral (DRR) to request an application be withdrawn. Contacting DRR directly may now be done electronically. Requesting the withdrawal of an application will remain available while the application has not undergone review and the summary statement posted.
For more details on the features listed above, please review the original announcement. For more information concerning Prior Approval for Withdrawals, please see Guide Notice NOT-OD-16-143 and the Prior Approval section in the eRA Commons online help.
The National Heart, Lung, and Blood Institute (NHLBI) have announced an important clarification impacting years of support for both new and renewal K24 funding. The maximum years of support is capped at 10 years. Review the full notice for more details.
The NIH Extramural Nexus Updates for August 2016 are now available. Some highlighted stories include: