tissue samples, tissue arrays, cells, microorganisms, probes and services for your research.
|A:||All of the tissues in our Tissue bank come from hospitals and clinics in the U.S. However, we do have international clinic partners that can be access when necessary.|
|A:||After surgery, tissue samples are put into formalin and brought to the pathology department of our collaborating hospitals. This process occurs less than 10 minutes after surgery and before the fixation.|
|A:||For post mortem tissues, the typical time in formalin fixative depends on the duration of procedures performed after death, including the acquisition of consent from the family. Nevertheless, the post mortem interval is less than six hours.|
|A:||Age, Sex, Race, Histological diagnosis, Differentiation grade, TNM, Stage, Tumor size, Date of surgery, etc.|
|A:||We have tested that the antigenicity was not lost (no significant difference in statistics) with paraffin tissue sections kept in a refrigerator (4°C) dated 4 years ago.|
|A:||Standard sample size is 0.5*1*1 cm.|
|A:||Standard sample size is 0.5-1 gram. Tissue samples of 2-3 gram are available upon request.|
|A:||All fresh tissue samples are collected by certified medical pathologists and are snap-frozen in liquid nitrogen within 30 minutes of surgery excision.|
|A:||Frozen: All frozen shipments are shipped on dry ice.
FFPE & TMA: FFPE specimen and TMA’s are packaged in slide cases and clam shells for protection.
Primary cells are cells taken directly from living tissue and established for growth in vitro. Primary cells have a finite lifespan and are widely used because they retain many of the markers seen in vivo. Primary cells from different species allow you to highlight potential differences between humans and preclinical test species. Before in vivo studies, using primary cells can refine doses and reduce the number of animals required for preclinical toxicology. Human primary cells can be used to determine accuracy of extrapolating human data from an animal model.
A cell line is a population of cells that has undergone a genetic transformation, resulting in indefinite growth potential. In practice, cell lines can be cultured through a very high number of subcultures, although some further genotypic, and therefore phenotypic, changes may occur at very high passage numbers.
Generally, cell lines lack many of the markers seen in vivo and also show very different marker profiles than primary cells.
Upon receiving the package, cryopreserved cells should be immediately transferred from the dry ice shipping container to a liquid nitrogen storage tank in order to prevent cells from thawing.
In the uncertain event that no dry ice is left in the package upon receiving, thaw and use the cells immediately.
Do not store the cells at -20°C or -80°C as this causes irreversible damage to the cells.
Note: Please refer to the cell product sheet for detailed instructions.
The following equations can be used to determine the maximum number of culture vessels that can be set up:
The effective growth areas for common tissue culture ware are listed below:
|A:||After thawing and plating the cryopreserved cells, the first medium change should be done after 24 hours or overnight, so that both residual DMSO and any dead cells are removed. In general, the medium should be changed every 2-3 days hours depending on the confluency of the cells until the cells are ready to be passaged.|
|A:||We uses the term "population doubling" instead of "passage" for describing the growth potential of the cells. A population doubling is a two-fold increase in the total number of cells in culture. The term passage number refers to the number of times that a cell population has been removed from the culture vessel and undergone a subculture (passage) process. Because the split ratios varies in different researchers when they subculture, it is difficult to predict how many passages can be obtained with a particular primary cell. Our primary cells are guaranteed for a specified number of population doublings on the cell product sheet.|
|A:||We do not recommend our customers refreeze primary cells. The cryopreservation process may result in altered growth performance of the cells.|
|A:||The presence of flocculants in FBS is due to lipoprotein precipitates – these are normal and are not harmful to cells. Customers can centrifuge briefly at 400g and take the supernatant to remove the precipitates, though it is not necessary.|
|A:||We do not recommend to spin cells out of cryopreservation medium before plating. Centrifugation can be harmful to cells, particularly if inappropriately high speeds are used. DMSO will be sufficiently diluted in medium when you plate the cells. For example, if you plate the whole cryovial (one milliliter) of cells in a T-75 flask with 15 ml of medium, the DMSO concentration will be less than 0.67% (v/v).Therefore, our product instructions include a detailed protocol which involves diluting the cells into culture medium at the recommended seeding density and volume of medium.|
|A:||Stem cells are a class of undifferentiated cells that have the remarkable potential to develop into many different cell types in the body. A stem cell is essentially a “blank” cell, capable of becoming another more differentiated cell type in the body with a more specialized function, such as a skin cell, a muscle cell, or a nerve cell. There are three classes of stem cells: totipotent, multipotent, and pluripotent.|
|A:||It may vary from different types of stem cells. For pluripotent stem cells which are derived from the inner cell mass of blastocysts or induced by transcription factors from somatic cells, hPSC can self-renew indefinitely. Stem cells or progenitor cells derived from adult tissues usually have limited self-renewal and differentiate eventually, such as neural progenitors. Our human mesenchymal stem cells are guaranteed for 15 population doublings.|
|A:||Expanding, passaging, or re-freezing hPSC-derived cardiomyocytes are not recommended.|
|A:||Embryonic stem cells (ESCs) are derived from the embryo and have the potential to become all the different cell types of the body (pluripotency). Somatic stem cells, sometimes called adult stem cells, are found in organs or tissues, can self-renew and yield the differentiated cell types comprising that organ or tissue (multipotency), and are important for maintenance and repair of the organ or tissue. Cord blood stem cells can be isolated from the umbilical cord of newborn infants and are less mature than adult stem cells. Cord blood stem cells are a type of somatic stem cell. Somatic stem cells are restricted in the types of cells they can produce in the lab.|
|A:||In situ hybridization indicates the localization of gene ex
|A:||Bacterial artificial chromosome (BAC) and P1-derived artificial chromosome (PAC) cloning systems, developed in the 1990s, are ideal cloning systems for carrying DNA fragments 100 to 300 kb in size. These libraries, including the RPCI-11 human female library and RPCI-23 mouse male library, are amenable to genomic analysis, since their DNAs are easily prepared and manipulated.|
|A:||For good results on older slides, the slides should not be stored dry at room temperature. They should be stored either in 100% ethanol at -20°C, or in a plastic box covered in saran wrap at -20°C or -80°C. Slides stored in this way can be used for several years.|
|A:||RNA probes should be between 250 to 1500 bases in length. Probes approximately 800 bases long exhibit the highest sensitivity and specificity. Ideally transcription templates should allow for transcription of both probe (antisense strand) and negative control (sense strand) RNAs. Cloning into a vector with opposable promoters will achieve this. Circular templates must be linearized before making a probe. PCR templates can also be used for this purpose. DNA probes can also provide high sensitivity for in situ hybridization.. However, they do not hybridize as strongly to the target mRNA molecules as RNA probes. Therefore, formaldehyde should not be used in the post hybridization washes when using DNA probes.|