Step	Problem	Possible Cause	Solution
1C	Brain is soft rather than hard	Poor perfusion	Discard, try another animal
	Brain appears bloodied		Discard, try another animal
	Liver does not turn pink		Discard, try another animal
	Fixation solution coming out of the nose or mouth of animal	Discard, try another animal	Use ideal perfusion pressure (~150 mmHg)
1, 2, 43	Tissue dark and murky looking, uneven membranes	Poor initial fixation, unhealthy tissue	Use only healthiest tissue for experiments, If poor perfusion or sick animals, discard. Use fresh fixatives only
		Inadequate rinsing between osmication and TCH treatment	Rinse well before and after osmium and TCH steps.
23, 25	Block chipping or tissue falling out of section	Inadequate infiltration	Be sure to infiltrate overnight on rotator for 2 nights
		Using EM trimmer blade too fast	Approach block slowly
	Block center soft	Inadequate infiltration	Longer infiltration, use only freshly prepared resins for infiltration and embedding
28.32	Ribbon curves	Top and bottom of block face not parallel, uneven sides	Re-trim block with fresh razor blade or diamond trimming tool
29	Ribbon not sticking together	Not enough glue on top and bottom of block face	Add more glue to top and bottom of block face
44	Charging of specimen in SEM	Not enough carbon coating or copper tape on coverslips	Remove sample and try more tape or carbon coat the surface
	Beam damage, breaks in section	Beam too bright	Try using lower voltage, reduce kV and brightness
	Bubbling of sections, black blobs forming	Sections have too much moisture	Allow sections to air dry then store under vacuum for 24 hours