Table 1:

Exosome abundance in various sources based on purification protocol.

Source	Method of Isolation	Concentration**	Reference
Human Origin
Adipose	Sucrose-Cushion Ultracentrifugation	1.86×1011 particles/L growth media	[105]
Stem Cells	Ultracentrifugation	1.02×1011 particles/L growth media	[105]
Bone	Ultracentrifugation	6.53–10.4 ×1012 particles/L growth media	[106]
Marrow	Sucrose-Cushion Ultracentrifugation	2.33×1011 particles/L growth media	[105]
MSC* Media	Ultracentrifugation	6.66×1010 particles/L growth media	[105]
Breast Milk	Ultracentrifugation	8.06×1013 particles/L milk	[48]
Saliva	Commercial Exosome Isolation Reagent (ExoQuick)	3.1×1013 particles/L saliva	[46]
Semen	Commercial Exosome Isolation Reagent (ExoQuick)	approx. 1015 particles/L semen	[107]
Urine	Ultracentrifugation/S ize Exclusion Chromatography	8.1×1012 particles/L urine	[45]
Wharton′s Jelly-Derived MSC* Media	Sucrose-Cushion Ultracentrifugation	8.66×109 particles/L growth media	[108]
	Total Exosome Isolation Reagent (Thermofisher)	2.93×109 particles/L growth media	[108]
	Ultracentrifugation	6.93×109 particles/L growth media	[108]
Whole Blood	Separation by Acoustofluidics	8.42×1013 particles/L whole blood***	109]
Bovine Origin
Raw Milk	Ultracentrifugation	1.4×1014 particles/L milk	[48]
	Ultracentrifugation	2.8×1014 particles/L milk****	*****

^*MSC = mesenchymal stem cell

^**Exosomes have been isolated from many different bodily fluids and conditioned media from various cell cultures. Different methods can affect the yield of isolation. To facilitate easier comparison, reported abundances were all converted to particles per liter.

^***Authors report in the text and in the figure legend quantification in particles per microliter. In the figure itself, the axis is labeled particles per milliliter. The figure label is likely a typo so particles per microliter was used for calculation.

^****The particle concentration per liter of raw milk is higher since only 70% of the material was subjected to the final ultracentrifugation step.

^*****Personal communication with Jeyaprakash Jeyabalan, Margaret Wallen, Wendy Spencer, and Ramesh Gupta of 3P Biotechnologies, Inc.