Description

CD45.1 C57BL/6 Bone Marrow cells

CD45.1 bone marrow cells come from C57BL/6 congenic mice that express the CD45.1 allele. CD45 itself is a protein tyrosine phosphatase receptor expressed on all hematopoietic cells except mature erythrocytes and platelets and is encoded by the Ptprc gene. Wild-type C57BL/6 mice normally carry the Ptprc^b (CD45.2) allele while the other (congenic) strain carries the Ptprc^a (CD45.1) allele on the same C57BL/6 genetic background.

Application for CD45.1 and CD45.2 cells

CD45.1 and CD45.2 cells are widely used in transplant and adoptive transfer studies to track the donor and host cells through the different alleles. In most transfer experiments, leukocytes expressing CD45.1 are transferred into wild-type C57BL/6 mice and then identified using an antibody specific for CD45.1. Similarly, cells expressing CD45.2 can be distinguished using antibodies that recognize CD45.2.

Cells from congenic mice that are genetically engineered (knockout or transgenic mice) can also be used in in vitro experiments to track cell development. Cells from knockout mice on a CD45.1 background can be mixed in culture with CD45.2 wild-type cells to understand the role of that specific gene in cell lineage fate decisions in a wild-type environment. Similar to the animal studies, antibodies against CD45.1 and CD45.2 can be used to distinguish the origin of the cells and track their outcomes. These experiments are faster and easier to perform and analyze compared to animal transfer studies.

CD45.1 bone marrow cells can also be used generate mature monocytes and macrophages from progenitor cells in the marrow. These cells are then typically used in co-culture assays with immune cells from a genetically engineered CD45.2 mouse to assess the role of the gene that is lost (knockout mouse) or manipulated (transgenic mouse).

Isolation of CD45.1 Bone Marrow Cells

Bone Marrow Collection and Isolation of Cells

Bone marrow is isolated responsibly from C57BL/6 CD45.1 congenic mice at third party facilities. These facilities are vetted to ensure they operate according to local regulations and laws. Since the facility is local, the marrow is quickly transported to iQ’s facility for processing.

At our facility, bone marrow is carefully removed from the tissue and mechanically dissociated to obtain a single cell suspension under sterile conditions. The suspension is carefully passed through a filter to remove any aggregates, and subsequently depleted of red blood cells. The bone marrow is then frozen based on iQ Biosciences’ quality-controlled cryopreservation protocol to promote recoverability and viability once in the end user’s hands.

Expression of CD45.1

A small aliquot of cells was tested for CD45.1 by flow cytometric analysis. Expression of CD45.1 was > 99%.

Cryopreservation and Storage

CD45.1 bone marrow cells are cryopreserved carefully using iQ Biosciences’ cryopreservation protocol that ensures high viability (typically > 70%) after thawing.

Cells should be stored at < -120°C once they are received, such as within a liquid nitrogen tank (vapor phase).