Fine and uniform microwells are processed on the bottom surface of the WELLBAG with a non-cell-adhesive coating, while the top surface of the WELLBAG has an overhang part. When the cell suspension is injected into the bag through the injection port, it distributs almost early evenly throughout the bag. After letting it sit, each microwell contains approximately the same number of cells, resulting in uniform spheroid sizes forming in each microwell.

*The image shown is based on the WELLBAG-S500, which has a cell diameter of 500 µm. The WELLBAG-S350 and L-350 have a diameter of 350 µm..*

1) WELLBAG is a closed bag system which reduces the contamination risk of bacteria and foreign substances 

2) Efficient gas exchange due to high gas permeability film

3) Easy collection of spheroids after the culture: Turn the bag upside down to drop the formed spheroids, and then collect the spheroids with a syringe.

4) The necessary high safety levels for cell culture have been achieved. (Safety standards according to the Japanese Pharmacopoeia)

• Cytotoxicity test Confirmed
• Leachable test Confirmed
• Ashing test Confirmed
• Endotoxin test Less than 0.25EU/mL
• Sterility Radiation Sterilization

WELLBAG-S500 has 18,000 microwells with a well diameter of 500um, while WELLBAG-S350 has 32,000 microwells with a well diameter of 350um. Both bags has the same size, allowing the use of the same dedicated holder.

WELLBAG-L350 is a scale-up product from the WELLBAG-S series products. It has 20 times culture area of WELLBAG-S series. The number of wells is about 36 times that of S500 and about 20 times that of S350. The bag is A3 size and it can be placed in a standard type incubator with a dedicated holder

Name	WELLBAG-S350	WELLBAG-S500	WELLBAG-S870	WELLBAG-S1260	WELLBAG-L350
Well Diameter	350 µm	500 µm	870 µm	1260 µm	500 µm
Number of Wells	ca. 32,000	ca. 18,000	ca. 6,300	ca. 3,100	ca. 650,000
Well diameter appearance	Stamped with 32K	Stamped with 18 K	Stamped with 6.3 K	Stamped with 3.1 K
Well cross-section
Air bubble removal method	Incubation Method	Manual Method & Incubation Method			Incubation Method
Outer dimensions	72 mm x 120 mm				292 × 412 mm
Material	Polyethylene with non-cell adhesion coating
Culture Area	50 cm2				1,000 cm²
Medium volume	10-20 mL				400 mL
Cat. No.	11020-05（5 bags） 11020-10（10 bags） 11020-00（100 bags）	11000-05（5 bags） 11000-10（10 bags） 11000-00（100 bags）	11040-05（5 bags） 11040-10（10 bags） 11040-00（100 bags）	11060-05（5 bags） 11060-10（10 bags） 11060-00（100 bags）	11020-01 (1 bag) 11020-05 (5 bags)

 To help differentiate between WELLBAG-S350 and S500, the WELLBAG-S350 is marked with "32K" on the seal of the bag.

By attaching the WELLBAG to a dedicated holder, the movement of spheroids between wells is suppressed and portability becomes possible. Parts of the base plate and holding plate are transparent, allowing microscopic observation while attached.

Holder for WELLBAG-S500 and WELLBAG-S350

Holder for WELLBAG-L350

 WELLBAG-S500 Operation Overview Video

WELLBAG-L350 (large size) Operation Video

WELLBAG System Operation Video

• Microwell bag culture for large-scale production of homogeneous islet-like clusters,  Ryo S, et.al., Scientific Reports 12, Article number 5221, 2022.