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Catalogue No.


Cell Line Name


Cell Line Description

From a set of packaging cell lines useful for generating helper-free recombinant retroviruses with amphotropic host ranges. Two mutant Moloney murine leukaemia virus-derived proviral genomes carrying complementary mutations in the gag-pol or env regions were sequentially introduced into NIH 3T3 cells by co-transformation. Each genome contained a deletion of the Psi sequence necessary for the efficient encapsulation of retroviral genomes into virus particles and additional alterations at the 3'end of the provirus. Psi-CRIP can be used to isolate clones that stably produce high titres (1000,000cfu/ml) of recombinant retroviruses with amphotropic host ranges. Viral producers derived from Psi-CRIP do not transfer the packaging function or yield helper virus.



Amphotrophic helper-free recombinant retroviral packaging cell line.

Tissue of Origin



Not specified


Amphotropic helper-free recombinant retroviral packaging


None Stated

Culture Conditions

Cell Type


Subculture Routine

Split sub-confluent cultures (70-80%) 1:3 to 1:6 i.e. seeding at 2-4 x 10,000 cells/cm² using 0.05% trypsin or trypsin/EDTA; 5-10% CO₂, 37°C.

Culture Medium

DMEM + 2mM Glutamine + 10% Foetal Bovine Serum (FBS) (NB. The results obtained by the depositor were gained using 10% Calf Serum (CS)).

Growth Mode


Additional Info


Dr J Liechty / Dr S K Spratt, Somatix Therapy Corporation, Alameda, California

Country of Origin

United States

GMO Status

Genetically Modified Organism Class 1 (GMO1)

Hazard Group (ACDP)

Hazard Group (ACDP) 2



Proc Natl Acad Sci, USA 1988;85:6460

Available Formats

  • Frozen

If use of this culture results in a scientific publication, it should be cited in the publication as: Psi-CRIP (ECACC 94090901).

Unless specified otherwise, at ECACC we routinely handle all of our cell lines at containment level 2 in accordance with the ACDP guidelines (Advisory Committee on Dangerous Pathogens) (UK). All cell cultures have the potential to carry as yet unidentified adventitious agents. It is the responsibility of the end user to ensure that their facilities comply with biosafety regulations for their own country. ACDP Guidance: Biological agents: Managing the risks in laboratories and healthcare premises.

The Culture Collections represent deposits of cultures from world-wide sources. While every effort is made to ensure details distributed by Culture Collections are accurate, Culture Collections cannot be held responsible for any inaccuracies in the data supplied. References where quoted are mainly attributed to the establishment of the cell culture and not for any specific property of the cell line, therefore further references should be obtained regarding cell culture characteristics. Passage numbers where given act only as a guide and Culture Collections does not guarantee the passage number stated will be the passage number received by the customer.

Cultures supplied by Culture Collections are for research purposes only. Enquiries regarding the commercial use of a cell line are referred to the depositor of the cell line. Some cell lines have additional special release conditions such as the requirement for a material transfer agreement to be completed by the potential recipient prior to the supply of the cell line. Please view the Terms & Conditions of Supply for more information.