A rapid microbiopsy system to improve the preservation of biological samples prior to high-pressure freezing.
A microbiopsy system for fast excision and transfer of biological specimens from donor to high-pressure freezer was developed. With a modified, commercially available, Promag 1.2 biopsy gun, tissue samples can be excised with a size small enough (0.6 mm x 1.2 mm x 0.3 mm) to be easily transferred into a newly designed specimen platelet. A self-made transfer unit allows fast transfer of the specimen from the needle into the specimen platelet. The platelet is then fixed in a commercially available specimen holder of a high-pressure freezing machine (EM PACT, Leica Microsystems, Vienna, Austria) and frozen therein. The time required by a well-instructed (but not experienced) person to execute all steps is in the range of half a minute. This period is considered short enough to maintain the excised tissue pieces close to their native state. We show that a range of animal tissues (liver, brain, kidney and muscle) are well preserved. To prove the quality of freezing achieved with the system, we show vitrified ivy leaves high-pressure frozen in the new specimen platelet.
D000818:Animals; D001706:Biopsy; D001921:Brain / Q000648:ultrastructure; D015925:Cryopreservation / Q000295:instrumentation* / Q000379:methods*; D016616:Cryoultramicrotomy; D017110:Freeze Substitution; D005615:Freezing; D007668:Kidney / Q000648:ultrastructure; D008099:Liver / Q000648:ultrastructure; D008854:Microscopy, Electron; D009132:Muscles / Q000648:ultrastructure; D018515:Plant Leaves / Q000648:ultrastructure; D011312:Pressure; D051381:Rats; D013048:Specimen Handling / Q000379:methods; D013997:Time Factors