Lentiviral Vector Building Service

Lentivirus is a genetic tool based on the human immunodeficiency virus (HIV), which has eliminated the virulence gene and is a pseudotyped virus with a high safety profile. Lentivirus can infect both dividing and non-dividing cells and integrate exogenous genes into the cellular genome for efficient gene expression. Lifeasible provides a lentiviral packaging service which improves the lentiviral packaging process in terms of viral titer, purity, activity, and consistency.

• Expression lentivirus packaging. Packaging of gene expression lentivirus, detection of lentiviral titer.
• shRNA lentivirus packaging. We use shRNA or siRNA sequences provided by customers to construct shRNA lentiviral vectors, package shRNA lentiviruses, and measure lentiviral titers.
• 3+1 shRNA lentiviral packaging. We design and construct 3 shRNA lentiviral vectors for gene sequences, transfect 293T cells with shRNA plasmids for interference efficiency testing, package lentivirus with the shRNA plasmid with the highest interference efficiency, and test lentiviral titer.

Type of virus

• VSV-G pseudoviralized third-generation lentivirus.
• VSV-G pseudoviralized second-generation lentivirus.
• Non-integrating lentivirus.
• Lentiviruses that are pseudoviralized using other membrane proteins, e.g., coronavirus spiking proteins.
• Lentiviruses with bare surfaces without membrane proteins can be used as negative controls for transduction.

Service flow

• The third-generation lentiviral packaging systems we routinely use include transfer plasmid, envelope plasmid, and packaging plasmids, and we cotransfected packaging cells with these plasmids. The packaging plasmids were Gag/Pol expression plasmid and Rev expression plasmid, respectively.
• In the cell, the transfer plasmid transcribed the HIV RNA genome carrying the gene of interest, which assembled into viral particles with the capsid structural proteins, enzymes, and regulatory proteins expressed by the packaging plasmid. It is then translocated to the inner side of the cell membrane to form an enveloped virus secreted extracellularly. The VSV-G membrane protein expressed by the membrane protein particle is anchored to the cell membrane and becomes, along with the cell membrane, the virus's membrane as it matures. After brief incubation of the cells, the supernatant is collected, centrifuged to remove cellular debris, and filtered.
• PEG concentrates on the virus particles. For ultra-purified lentivirus, we will use sucrose centrifugation to purify and concentrate the virus further.
• We will perform iter determination, bioburden test (for bacteria, fungi), mycoplasma test, etc., on the virus. If the transfer vector encodes a fluorescent protein, we transduce the virus into cells to determine the corresponding fluorescent expression (transduction test). In addition, for ultra-purified lentiviruses, we can perform the endotoxin test.

Common vector selection

Technical advantages

• Lentivirus is an integrated virus, which can realize the stable and lasting expression of exogenous genes or shRNA or miRNA, which is more suitable for gene function research.
• Higher transduction efficiency can efficiently express exogenous genes.
• High lentivirus infection rate, wide range of applications (can infect dividing and non-dividing cells), especially suitable for cells with low plasmid transfection efficiency.
• Easy packaging process can obtain many viruses at one time and high titer.

If you need GMP-grade lentivirus preparation services, please feel free to contact us for information.