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13 things to know about Quasi Vivo® Systems

QV products in sterile hoodLast month, we announced that we are the exclusive distributors of the Quasi Vivo® cell culture flow systems in the US and Canada. In this blog post, we would like to address common questions regarding the set-up, maintenance, and applications of the flexible research tool.

1. You can optimize the flow rate for a specific cell type.

Use the guidelines we have given in the Quasi Vivo® User Manual to find a range of possible flow rates.  Set up the system and compare the viability of cells cultured for 24 hours (or some other appropriate time scale for your cell type) at each flow rate in this range.  Cells can be transferred from the chambers into a 24 well plate and assays may be performed to assess viability.  The flow rate which produced the highest viability compared to the other flow rates and the static control should be used.

  1. The system is relatively easy to use.

The system is provided as a modular kit that can be connected in any configuration that you choose, to allow a variety of experiments to be devised. For more details on how to set up a system, please consult the user manual included with each Quasi Vivo® kit (also available here). To supplement these documents, attend our upcoming two-day training workshop on February 25-26, 2016.

  1. QV500 and QV600 chambers may be used more than once.

QV500 and QV600 chambers can be autoclaved up to 3 times. QV900 chambers cannot be autoclaved and are not recommended for reuse. For reservoir bottles and tubing, follow the manufacturer’s instructions. Some tubing cannot be autoclaved so sterilize with 70% alcohol if needed.

  1. The system design discourages detached cells from re-attaching elsewhere.

The silicone used in the system discourages cells from attaching, so even if cells are dislodged by flow, they will not attach elsewhere in the system.

  1. The system is designed for recirculating media.

The system is designed for recirculating media, and we recommend this setup for most applications. Recirculation allows cells to condition the medium with growth factors and signaling molecules, and therefore improves growth, viability, and the system’s ability to model the in vivo environment. However, the Quasi Vivo® system can be made into single pass if required.

  1. Quasi Vivo® is suitable for Western blot (protein immunoblot).

This would depend on the protein to be studied. A typical basic system would consist of 2 chambers, each containing between 250K-300K cells depending on cell types. Highly-expressed proteins such as those in ribosomes should be detectable, but for proteins with lower expression, more chambers may be required.

  1. Quasi Vivo® may be used to perform enzymatic studies.

The system is designed for enzymatic studies. Although, the quantity of cell material needed will depend on the nature of the study, the enzyme, and its relative expression.

  1. Even if gene regulation is unaffected by flow, the cell culture will benefit.

So far, the focus of gene study has been on a small number of important genes in hepatocytes, all of which were found to be upregulated under flow compared to static.

There may be some genes whose regulation is unaffected by the presence of flow, but the cell and culture as a whole will benefit from both the nutrients being refreshed and toxins/metabolic products taken away.

  1. Pumps may be used inside or outside of an incubator.

It can be either; this will depend on investigator preference as well as the specifications of the pump model used.  According to our users, the inside/outside split is about 50:50.  We can make recommendations for pumps that will work in humid or non-humid incubators if needed.

  1. Six chambers may be connected to one reservoir bottle.

Up to six chambers can be connected to a single 30 mL reservoir bottle. At the time of printing, the maximum number of chambers used in an experiment, in multiple circuits, was 32.

  1. The system may be used to represent the interaction of various organs.

Cells from different tissues can be cultured separately and connected together, to model organ interaction.

  1. The system enables cells to be cultured for a comparatively extended period of time.

Hepatocytes have been cultured for a month and have retained their phenotype and CYP gene expression. The length of the experiment can be varied from 1 to 3 day experiments, to week or month-long studies and potentially longer.

  1. The Quasi Vivo® system has a variety of experimental uses.

The Quasi Vivo® system is highly flexible, and can be configured for a wide range of experimental designs.  Different chamber models can also be connected, to model interactions between cell types in different environments.

Contact our experts for more information.  Also, for an in-depth introduction to Quasi Vivo®, register for our two-day training workshop.

We offer great discounts on bulk orders of cryopreserved hepatocytes. Contact us for more information.