Table 1.

Summary of current optical clearing techniques.

		Clearing Time	Immunostaining/ Fluorescent Protein#	Lipid Preservation	Size Change	Final RI	Citation
Solvent-based	BABB	Days	I	No	Shrinkage	1.55	Dodt et al., 2007
	FluoClearBABB	Days, Weeks	F	No	Shrinkage	1.56	Schwarz et al., 2015
	3DISCO	Hours, Days	I (limited)/ F (couple of days)	No	Shrinkage	1.55	Ertürk et al., 2012a; Ertürk et al., 2012 (b)
	iDISCO	Hours, Days	I/ F (couple of days)	No	Shrinkage	1.56	Renier et al., 2014
	iDISCO plus	Weeks	I	No	ShrinkageM	1.56	Renier et al., 2016
	uDISCO	Hours, Days	I/F	No	Up to 65 % Shrinkage	1.57	Pan et al., 2016
	vDISCO	Weeks, Months	I/F	No	Shrinkage	1.55	Cai et al., 2018
	FDISCO	Days	I/F	No	Shrinkage	1.56	Qi et al., 2019
	sDISCO	Days, Months	F	No	Shrinkage	1.55; 1.56	Hahn et al., 2019
	sPEGASOS	Days, Weeks	I/F	No	Shrinkage	1.54	Jing et al., 2018
Simple Immersion	Sucrose	Days	I/F	No	Shrinkage	1.44	Tsai et al., 2009
	FocusClear	Hours, Days	I/F	Yes	No Change	1.47	Chiang et al., 2002
	ClearT	Hours, Days	I	Yes	No Change	1.44	Kuwajima et al., 2013
	ClearT2	Hours, Days	I/F	Yes	No Change	1.44	Kuwajima et al., 2013
	SeeDB	Days	F	Yes	No Change	1.48	Ke et al., 2013
	SeeDB2 G/S	Days	F	Yes	ShrinkageM	G-1.46; S-1.52	Ke et al., 2016
	FRUIT	Days	F	Yes	ExpansionM	1.48	Hou et al., 2015
	TDE	Days, Weeks	I/F	No	No Change	1.42	Costantini et al., 2015; Aoyagi et al., 2015; Staudt et al., 2007
	FASTClear	Weeks	I/F	No	ShrinkageM	1.42-1.56	Liu et al., 2017
	Ce3D	Weeks	I/F	No	ShrinkageM	1.49	Li et al., 2017
Hyperhydration	ScaleA2	Weeks	I (limited)/ F	No	Expansion	1.38	Hama et al., 2011
	ScaleU2	Months	I (limited)/ F	No	No Change	1.38	Hama et al., 2011
	ScaleS	Weeks	I/F	No	ShrinkageM	1.47	Hama et al., 2015
	CUBIC	Days	I/ F	No	Expansion	1.38; 1.48	Susaki et al., 2014
	CUBIC-L CUBIC-R	Days, Weeks	I/F	No	ExpansionM	1.44-1.52	Tainaka et al., 2018; Kubota et al., 2017
	Whole-Body CUBIC	Days	I/ F	No	Expansion	1.38	Tainaka et al., 2014
	ScaleCUBIC (1,2)	Days, Weeks	F	No	Expansion	~1.49	Susaki et al., 2014 (a); Susaki et al., 2015 (b)
	UbasM	Days, Weeks	I/F	No	ExpansionM	1.45-1.48	Chen et al., 2017
	CUBIC-X	Days, Weeks	F	No	Expansion	1.47	Murakami et al., 2018
Hydrogel Embedding	CLARITY	Days	I/F	No	ExpansionM	1.45	Chung et al., 2013
	Bone CLARITY	Days, Weeks	F	No	ShrinkageM	1.47	Greenbaum et al., 2017
	PACT	Days, Weeks	I/F	No	ExpansionM	1.38-1.48	Yang et al., 2014
	PARS	Days	I/F	No	No Change	1.38-1.49	Yang et al., 2014
	ACT-PRESTO	Hours, Days	I/F	No	Expansion	1.47	Lee et al., 2016
	SWITCH	Days, Weeks	I	No	ShrinkageM	1.47	Murray et al., 2015
	SCM	Hours, Weeks	I/F	No	Expansion	1.47	Sung et al., 2016
	Stochastic electrotransport	Days	I/F	No	ExpansionT	1.47	Kim et al., 2015
	SHIELD	Days, Weeks	I/F (limited)	No	Expansion	1.46	Park et al., 2019
	iExM†	Days	I	No	Expansion up to ~20x	1.33	Chang et al., 2017a
	MAP†	Days	I/F	No	Expansion up to 4-5x	1.33	Ku et al., 2016

RI, refractive index; I, immunostaining; F, fluorescent protein.

^#Indicates whether immunolabeling and/or fluorescent protein emission was demonstrated in the original publication.

^†Hydrogel embedding followed by hyperhydration.

^MMinimal

^TTransient.