The purpose of fixing biological specimens is to preserve the sample as close to its natural state as possible so that it may be examined later. Conventional fixation methods typically use physical means such as heat or freeze-drying, or chemical means such as aldehydes or alcohols, to preserve a biological specimen for further preparation and examination. These conventional methods suffer from a variety of limitations. Importantly, fixation using one or more of these current methods may disrupt the structure and composition of the cellular components, creating fixed samples that do not truly reflect the properties of the living cells or tissues. Also conventional fixation methods often take several hours, meaning that the sample structure or properties may be altered while the fixation is occurring. Furthermore, almost all fixation chemicals are extremely hazardous and special precautions must be taken to avoid accidental or chronic overexposure.
Air Force Researchers have developed a laser-based rapid fixation system to reduce or eliminate many of the physiological or chemical changes in the sample that are commonly observed with other fixation processes. This system may have particular importance for immunohistochemical or immunofluorescence methods that visualize molecular markers in cells using antibodies.
- May be used to preserve samples for observation by various techniques including tunneling electron microscopy, scanning electron microscopy, and atomic force microscopy, as well as to stabilize specimens for transportation
- Allows for a single region of interest of adjustable size to be fixed, while leaving the remainder of the cell culture or tissue viable
- Enables multi-time point studies, potentially within the same sample or specimen
- This system accommodates cells obtained by most cell culture methods including cell smear or cells isolated from a tissue section
- Cellular specimens may be stained, labeled, frozen, or otherwise treated and may be adherent or in suspension
- The system may be implemented as an integral part of a microscope or as a modular add-on for existing systems
- System may also be used as part of a portable device to allow for fixation and/or inactivation in remote locations
- Fixation may be performed by a layperson without formal training, reducing the number of specialists required at remote locations
- Published US application number 20160282237 available for license
- Potential for collaboration with Air Force researchers