Mirsky`s Fixative

Mirsky’s Fixative is a superior fixing agent for use in immunohistological and immunocytological protocols. Mirsky’s Fixative contains no formaldehyde or glutaraldehyde. Therefore, it has considerably reduced toxicity and virtually no odor. Mirsky’s Fixative is neutral, buffered, and isotonic (308 milliosmoles). Additionally, Mirsky’s Fixative does not contain toxic or hazardous buffers such as cacodylate or barbital. Hardening or shrinkage of tissue is considerably reduced.

Image of mouse embryonic oral epithelium fixed with Mirsky’s Fixative, showing expression of GFP and tdTOMATO. Image courtesy of Dr. Jan Prochazka, University of California, San Francisco.

Double reactive sites afford excellent crosslinking properties while maintaining sample enzyme activity. Samples processed in Mirsky’s Fixative for light microscopy can subsequently be used in electron microscopy procedures. Special buffer systems may be used in place of the buffer provided.

Mirsky’s Fixative is normally distributed as a concentrated two bottle system, although high throughput laboratories often use the single bottle ready-to-use format. The two-bottle system is comprised of Mirsky’s Fixative 10X Concentrate and Mirsky’s Fixative 10X Buffer. To reconstitute to working strength, add 1 part Mirsky’s Fixative 10X Buffer to 8 parts distilled or deionized water, mix thoroughly, then add 1 part Mirsky’s Fixative 10X Concentrate and mix again.

The two-bottle system has a shelf life of 12 months while the ready-to-use format has a shelf life of 30 days.

Method:

Use as a replacement for formalin and/or glutaraldehyde fixatives in immunohistological and immunocytological staining protocols. Tissue size is unlimited as long as the sample is no thicker than 0.5 cm in at least one plane to assure uniformity of tissue penetration. The gross visual appearance will be different than in formaldehyde and tissue may seem ‘raw’. This is due to double site binding of the fixative with a resultant reduction in tissue shrinkage. Microscopic examination of tissue morphology will be noticeably improved. This material is intended to maintain enzyme and antibody activity. For best results, tissue sections of high digestive enzyme content should be thoroughly rinsed in saline solution before fixation (e.g. trypsin in intestinal samples). Once fixed, tissue may be retained in Mirsky’s Fixative and ethanol indefinitely.

References:

Relieving Autophagy and 4EBP1 from Rapamycin Resistance
, Beat Nyfeler, et al. Molecular and Cellular Biology, July 2011, p. 2867–2876

Identification of a Small Molecule That Induces Mitotic Arrest Using a Simplified High-Content Screening Assay and Data Analysis Method, Christopher J. Wilson, et al. Journal of Biomolecular Screening 2006 11: 21