REAGENT or RESOURCE	SOURCE	IDENTIFIER
Biological samples
Human bone marrow	This paper	N/A
Chemicals, peptides, and recombinant proteins
Paraformaldehyde 16%, EM grade	Electron Microscopy Sciences	Cat#15710
Glutaraldehyde 25%, EM grade	Electron Microscopy Sciences	Cat#16220
Sodium cacodylate trihydrate	Sigma-Aldrich	Cat#C0250
PBS buffer (10× Dulbecco’s) powder	ITW Reagents	Cat#A0965
Evans Blue	Sigma-Aldrich	Cat#E2129
Certified low-melt agarose	Bio-Rad	Cat#161-3111
Glycid ether 100	Serva	Cat#21045
Dodecenylsuccinic acid anhydride (DDSA)	Serva	Cat#20755
Methylnadic anhydride (NMA)	Serva	Cat#29452
2,4,6-Tris(dimethylaminomethyl)phenol (DMP-30)	Serva	Cat#36975
Osmium tetroxide in H2O	Electron Microscopy Sciences	Cat#19150
Uranyl acetate in H2O	Serva	Cat#77870
Deposited data
Additional supplemental data	This paper	Mendeley Data: https://doi.org/10.17632/ct23zrnxc2.1
SerialEM scripts	This paper; Schorb et al.6; Dittrich et al.1	https://serialemscripts.nexperion.net/
SerialEM tools	This paper; Schorb et al.6; Dittrich et al.1	Github: https://git.embl.de/schorb/pyem/-/tree/master/applications
Software and algorithms
Konstanz Information Miner (KNIME)	Berthold et al.3	https://www.knime.com/
SerialEM	Mastronarde2; Schorb et al.6	https://bio3d.colorado.edu/SerialEM/
pyEM	Schorb et al.6	https://git.embl.de/schorb/pyem
IMOD – 4.10.42	Kremer et al., 1996; Mastronarde and Held7	https://bio3d.colorado.edu/imod/
ImageJ (Fiji) – 1.53	Schneider et al.4	https://imagej.net/software/fiji/
Other
Protein LoBind Tubes 1.5 mL	Eppendorf	Cat#0030108116
Serial Sectioning Protocol	SynapseWeb, K. M. Harris, PI; University of Texas	https://synapseweb.clm.utexas.edu/serial-sectioning