What is "G-Rex"?

G-Rex is Gas permeable Rapid Expansion cell culture technology that overcomes the limits of traditional plates, flasks, and bags.

What cell type is G-Rex designed for?

Any non-adherent cell type. It has been shown to be a powerful tool for culture of CTLs (Virus-Specific T cell), CAR-T, NK, TIL, Treg, CIK, as well as hybridoma, HeLa, CHO, Sf9 among others.

What advantages does G-Rex provide compared to other culture device options?

  • Saves money and time
  • Very simple and practical
  • Directly scalable from 2cm2 up to 500cm2 surface areas (with cell densities from 10 – 40 million per cm2)
  • Much more efficient use of medium
  • Greatly reduced feeding frequency
  • Far less labor
  • Cells can be recovered in very small volumes of medium (ie: High density harvest)
  • Can decrease the overall culture duration
  • Occupies very little space
  • No need for perfusion, mixing, or shaking
  • No capital equipment investment beyond standard incubators
  • Functionally closed from small to large scale

What is the key to the superiority of G-Rex?

It allows cells to reside on a highly gas permeable membrane submerged under an unconventionally high column of medium. No pumps, mixing, or shaking is needed for cells to receive a virtually unlimited supply of oxygen and nutrients on demand.

Do I need special equipment to operate G-Rex?

No, just place it in a standard cell culture incubator.

Is there a basic protocol or do I need to customize it for each cell type?

A basic protocol that is very effective for any non-adherent cell type can be found in the G-Rex Instruction Guide of the Applications Page. We recommend users start with the basic protocol and then optimize seeding densities, minimize interventions and maximize expansions while shortening culture duration.

Are there any basic expectations for the number of cells each device can produce?

Yes, cell capacity is a function of device surface area. G-Rex provides about 1 to 4 billion cells per 100 cm2 of surface area (normalized to 10 – 40 x106 cells/cm2).

How do I know how many cells are in the device at any given time?

There are two ways to accomplish this:

  1. As further detailed in the G-Rex Instructions Guide, count the cells by withdrawing the majority of media (~75%, possibly up to 90%) from the device, swirling the device to resuspend the cells from the gas permeable membrane into suspension and draw a representative cell sample.
  2. As further detailed in the G-Rex Instructions Guide, take a glucose sample. Measuring glucose depletion and/or lactate production has been shown to be an excellent surrogate measure for cell number.

Is there a typical feeding strategy?

Yes, as described in the G-Rex Instructions Guide.

Can G-Rex simplify the cell recovery process?

Yes, unlike cell harvest from flasks or bags, cells can be recovered in a fraction of the volume in G-Rex.

Should the cap be tightened?

Yes, gas transfer occurs via the bottom of the device so there is no need to leave the cap loose.

Are there any nuances about the device that I should know about?

  1. Unlike flasks, the medium color does not change quickly so pH cannot be determined by simply looking at the medium. The feeding strategies described in the G-Rex Instructions Guide (Applications Page) will ensure pH is acceptable at all times.
  2. BE CAREFUL to not puncture the bottom of the device with a pipette tip. The bottom is comprised of a thin silicone-based membrane and although very resilient, attempting to scrape it or rest your arm by leaning on it with a pipette can cause damage. To remove cells, dislodge them by swirling the medium in the device as described in the G-Rex Instructions Guide.

Is G-Rex producing cells for use in clinical applications?

Yes, G-Rex devices are registered as Class I medical devices and manufactured in accordance with 21 CFR Part 820 “QSR”. Contact us to discuss your specific application.

Are other versions of G-Rex going to be available?

Yes, G-Rex is a platform technology that is continually evolving to meet the needs of the biomedical research community. Please contact us to address your specific needs.

Can I reuse G-Rex?

No, G-Rex is designed as a disposable, single use device.

How do I optimize G-Rex for the best expansion of cells in the least amount of time?

Refer to the G-Rex Instructions Guide or contact us directly with questions.

What are the advantages offered by the G-Rex "M" series?

High cell density, reduced media usage, reduced labor, and shortened culture durations. This is accomplished through an optimal 10mL/cm2 ratio of media volume to surface area that allows cells to go from minimum densities to maximum cell densities without intervention in the least amount of time.