TheWell Vitrogel 水凝胶动物体内注射- Xenograft FAQ （英文版）
Q What is the injection volume of VitroGel?
A Most customers working with mice use an injection volume of 100-200 μL (depending on cell type). For rat models, the injection volume is about 500 μL.
Q What is the recommended number of cells for VitroGel injection?
A The typical implanting cell number is between 1 to 10 x 106 depending on different cell types. The cell suspension can be prepared in PBS to obtain 2-20 x 107 cells per mL and then be mixed with VitroGel at 1:1 ratio (v/v). The cell density can be adjusted based on the inoculation volume (e.g., 100 or 200 μL) as well as the mixing ratio between VitroGel: Cell suspension. Please check user protocols for different mixing ratios.
Q Do I need to keep the VitroGel-Cell mixture in an ice bucket?
A No. Unlike Matrigel, VitroGel is ready-to-use and can mix with a cell suspension at room temperature. After the hydrogel and cell suspension are mixed and transferred to a syringe, you can put the mixture on ice, or 4 degrees Celsius, for 5-10 minutes to accelerate the injectable hydrogel formation and ensure a homogenous cell suspension. After that, the hydrogel can be kept at room temperature for long-term injection. Alternately, if you don’t want to use cold temperature for any part of the protocol, simply put the hydrogel-cell mixture at room temperature for 15 minutes for gel stabilization before injection. VitroGel has a unique shear-thinning and rapid recovery property, which can maintain a long-term injectable status (hours) and excellent cell retention after injection without the needle clogging issue (Please check this page for more details and illustrated protocol).
Q How long does the VitroGel-Cell mixture retain its injectable status compared to Matrigel?
A As opposed to Matrigel, which has a fast solidification process when the temperature is higher than 10 degrees Celsius, the VitroGel-Cell mixture forms a soft injectable hydrogel. The hydrogel has a unique shear-thinning and rapid recovery property which enables it to retain its injectable status for months even (unless more culture is not added or for as long as the cells survive).
Q After injection with VitroGel, how efficient is cell retention?
A After injection, the sol-gel transition happens immediately, which rebuilds the mechanical strength of the hydrogel and holds cells within the hydrogel matrix. Hence, our hydrogel system has excellent cell retention after injection.
Q Do I have to add serum, growth factors, or supplements to the cell suspension before mixing with VitroGel?
A No. Adding supplements to the hydrogel matrix is not required. For most xenograft applications, preparing cells in PBS solution works extremely well with VitroGel. On the other hand, VitroGel is animal-origin free, which gives the flexibility for researchers to manipulate the supplement in a gel-cell mixture if needed.
Q If I want to add supplements to boost cell growth, what are the common growth factors or components used?
A The growth factors added depend on your application and system. The common ones include BSA, HSA, serum replacement, etc. If serum supplement is not a concern, you can also add FBS to give the system an extra push to see promising cell growth.
Q Does the addition of serum and other cytokines at a high concentration to the cell suspension before mixing with VitroGel lead to bubble formation?
A No, there is no issue with bubble formation due to the low viscosity of VitroGel. There is an option to warm the medium and hydrogel solution before mixing them, as this can help reduce the viscosity.
Q Can VitroGel be used for injection in mice at different sites?
A Yes, VitroGel allows for different injection sites like subcutaneous, orthotopic, IP, etc. Some injections that are difficult with an animal-based matrix can perform smoothly with VitroGel.
Q What is the tumor formation rate and growth kinetic in VitroGel?
A VitroGel performs extremely well for tumor formation. The tumor formation rate is almost 100% for typical cell types and even over 70% for some difficult cell types. In most cell types, the tumor growth kinetics in VitroGel are faster or equal to Matrigel.