Table 2 Isolation methods to obtain EVs from amniotic fluid

Exosomes [22]

Amniocentesis (approximately 16 weeks)

i) 300g, 20 min

ii) 10,000g, 20 min

100,000g, duration not clear

Sucrose density gradient centrifugation at 100,000g, 2.5 h

Exosomes [30]

Collection at labour/caesarean section

i) 2000g, 30 min

ii) 2000g 45 min

100,000g, 2 h

i) Filtration through a 0.22 μm filter

ii) Centrifugation at 100,000g, 2 h

Exosomes [31]

Collection at labour/caesarean section

i) 300g, 10 min

ii) 2000g, 30 min

iii) 12,000g, 45 min

Filtration through a 0.22-μm filter and centrifugation at 120,000g, 70 min, twice

EVs [32]

Caesarean section

i) 300g, 5 min

ii) 500g, 10 min

iii) 10,000g, 30 min in a cell sieve

100,000g, 2 h

i) Filtration through a 0.22 μm filter

ii) Size-exclusion chromatography

EVs [33]

Amniocentesis (17–36 weeks)

Commercial EV isolation Kit

Exosomes [34]

Amniocentesis

i) 300g, 20 min

ii) 10,000g, 20 min

100,000g, 2.5 h

Sucrose density centrifugation at 100,000g, 2.5 h

Exosomes (murine) [35]

Collection with a needle directed to amniotic cavity after euthanization

i) 300g, 20 min

ii) 10,000g, 30 min

120,000g, > 18 h

EVs [39]

Caesarean section

Filtration system (details unavailable)

100 000g, 3 h

Exosomes (sheep) [40]

Not specified

i) 300g, 10 min

ii) 2000g, 15 min

iii) 10,000g, 30 min

iv) Filtration through 0.22 μm-sized microfilter

100,000g, 1 h

EVs (commercial product: Zofin) [41, 42, 122]

Caesarean section

Centrifugation and filtration

EVs [53]

Not specified

i) 3000g, 20 min

ii) 20,000g, 20 min

Incubate with DTT 20,000g, 20 min

Exosomes [54]

Collection at labour/caesarean section

i) 300g, 10 min

ii) 2000g, 20 min

iii) 10,000g, 30 min

100,000g, 2 h

Commercial EV isolation Kit

Exosomes [55]

Amniocentesis (15–16 weeks)

i) 48,298g, 30 min

ii) Filtration through 0.22 µm filter

584,401g, 60 min

Microparticles [67]

Collection at labour/caesarean section

1500g, 15 min

13,000g, 2 min

Exosomes [68]

Amniocentesis (approximately 16 weeks)

i) 300g, 10 min

ii) 10,000g, 20 min

i) 100,000g, 2 or 18 h for human AF-EVs

ii) 120,000g, overnight for murine AF-EVs

Exosomes [70]

Amniocentesis

i) 300g, 5 min

ii) 1200g, 20 min

iii) 10,000g, 30 min

100,000g, 1 h

Sucrose density gradient centrifugation (1.08–1.24g sucrose/ml) at 150,000g, 12 h

EVs [72]

Caesarean section

i) 500g, 10 min

ii) 2000g, 15 min

iii) Filtered through a 0.22 μm

100,000g, 3 h

EVs [73]

Amniocentesis (16–17 weeks)

i) 300g, 10 min

ii) 2000g, 20 min

iii) 10,000g, 45 min

100,000g, 1 h

EVs [74]

Caesarean section

Commercial EV isolation Kit or 107,000g, 1.5 h

Exosomes [81]

Amniocentesis

i) 300g, 5 min

ii) 1200g, 20 min

iii) 10,000g, 30 min

100,000g, 1 h

EVs [84]

Amniocentesis

i) 1000g, 15 min

ii) 2000g, 15 min

iii) 3000g, 15 min

110,000g, 75 min

Exosomes [85]

Amniocentesis (19–23)

i) 300g, 10 min

ii) 2000g, 30 min

iii) 12,000g, 45 min

110,000g, 2 h

i) Filtration through a 0.22-μm filter

ii) Centrifugation at 110,000g, 70 min

Exosomes [86]

Amniocentesis (15–25 weeks)

Commercial EV isolation Kit

Exosomes [92]

Amniocentesis

(18–20 weeks)

Unclear

100,000g, duration unclear

EVs [93]

Amniocentesis (16–20 weeks)

400g, 10 min

EVs in the AF were stained (not isolated)

Microparticles [94]

Collection at Caesarean section

1500g, 15 min

18,000 rpm, 30 min

EVs [95]

Amniocentesis (15–18 weeks)

i) 250g, 5 min

ii) Filtration through a 0.1 µm pore membrane

20,000g, 30 min

EVs [96]

Amniocentesis (15–28 weeks)

Size exclusion chromatography

EVs [98]

Amniocentesis (approximately 17 weeks)

Commercial EV isolation Kit

EVs [69, 123]

Amniocentesis (16–18 weeks)

i) 300g, 10 min

ii) 3000g, 20 min

iii) 17,000g, 25 min

100,000g, 2 h

Sucrose density gradient centrifugation at 100,000g, 2 h OR ion-exchange chromatography

Exosomes [124]

Caesarean section

i) 300g, 10 min

ii) 2000g, 20 min

iii) 10,000g, 30 min

100,000g, 1 h

EVs [125]

Not specified

i) 3000g, 15 min

ii) 11,000g, 15 min

iii) 14,000g, 15 min

iv) Filtered through a 0.22 μm

100,000g, 1 h