Providing quality life science research reagents and services for customers developing innovative methods, processes, products and medicines. I would like to determine the TCID50 of influenza virus on MDCK cells with a viability test. MOI is related to pfu by the following formula: Multiplicity of infection (moi) = Plaque forming units (pfu) of virus used for infection / number of cells. Read O ur Lentivirus FAQ When the percentage of infected cells is at or below 20%, the number of integrations is approximately equal to the number of transduced cells. That is to say, if you have 1 million cells and you want an MOI of 5, you need 5 million lentivirus particles for your transduction. The MOI is expressed as a ratio of the number of IFU or TU added to the cells (IFU/cell or TU/cell). Ideally, it is best to aim for transducing less than half the cells so that most of the cells have been transduced with a single viral particle. So, this study presents a simple method to increase the transduction efficiency of K562 cells with a low multiplicity of infection (MOI) of the virus particle. I tried to make calculations but I'm not sure they are correct. The MOI describes the number of virus particles needed to infect one cell. Can I use this approach to determine the previously stated MOI ratios of my phage isolates? An MOI of 1 is equal number of cells and virus particles. My number of cells will not be the same... Should I convert this result in PFU ? Do I need to take into account just those wells where the cytopathic effect appears in more than 50% of inoculated tissue culture cells? Hey so I'm still fairly new to cell culturing and I am having trouble with the arithmetic for seeding desired number of cells. I am a little bit lost and all I read on the web didn't really help me. I have almost 100% of infected cells (GFP+) by infecting 250000 Jurkat cells by 10 microliters of lentiviral suspension, which were added to a cellular suspension of 250 microliters. The growth curves for cells treated with lentivirus at 60 and 150 MOI were similar to growth curves for control cells. How can I calculate the virus quantification by TCID50? If ten million virions are added, the MOI is ten. If you’re planning on using lentivirus for your next experiment, chances are you’re wondering how much virus to use. I seeded an exact number of cells in 96 well plate and do a serial dilution of the virus (90ul added to the cells). How can I use this to reinfect cells in T75 flask for example ? It is determined by plaque forming assay. This protocol can be used to titer lentiviral preparations that carry a fluorescence marker. To calculate the number of transducible viral particles in the viral stock, you need to know the number of cells transduced at a specific dilution factor of the stock virus. Using the chart below, the number of integrations per cell, or MOI (Multiplicity Of Infection), can be accurately estimated for cultures with up to 75% transduced cells (i.e., MOIs in the range of ~0.2-1.5). Include any dilution of the viral stock. For the above example, you should dilute 0.2 ml of the virus stock at least 1:12.5 to obtain 1,000,000 infectious particles per 0.2 ml, then this volume (0.2 ml x 12.5 = 2.5 ml) should be diluted appropriately to infect the number of vessels. I have seen a general protocol for determining MOI ratios in Adenovirus where MOI ratios were calculated using a formula No. Packaging, Titering, and Transduction of Lentiviral Constructs. Get Tips for Titering Your Lentivirus Genetic vaccines and therapy 2.1 (2004): 1. How much do I have to take to get MOI of 1 if I plate 10000 cells in a 12 well plate.Â, I would also like to know if these cells are enough or would be too much for 50% confluency. Determining the titer of your lentiviral vector allows you to control the multiplicity of infection (MOI) in downstream studies. This protocol was developed for Lenti-X 293T cells but can be adapted to a variety of target cell lines and selection markers. A Third Generation Lentivirus Vector with a Conditional Packaging System. cell).For example, when referring to a group of cells inoculated with virus particles, the multiplicity of infection or MOI is the ratio of the number of virus particles to the number of target cells present in a defined space. I will use lentivirus soon to integrate an shRNA in my cells. How does one interpret TCID50 and manage number of cell variations? In this case a MOI of 1 results in a Self-Inactivating Lentivirus for Safe and Efficient In Vivo Gene Delivery. One TU produces one integration event in target cells. Is shaking of the cultures necessary during MOI determination? Or What appropriate volume of both diluted phage lysate and host bacteria can I work with? Step 1: Select 6 MOI conditions to test For example, using a GFP Lentivirus, design a range of MOIs to use, let’s say, 6 conditions ranging from MOIs 1, 2, 5, 10, 15, and 30. Genemedi got a rich experience in lentivirus production and infection, you could find more information about lentivirus infections on this website: The University of Tennessee Medical Center at Knoxville. For example, if 2x106 cells is infected by 50 ml of virus with a titer of 108 pfu/ml. Multiplicity of infection (MOI) is a frequently used term in virology which refers to the number of virions that are added per cell during infection. For the non-dividing cells, like primary cells with a low infection efficiency, it is better to test a range of MOIs to determine the optimal MOI for infection and gene expression. How to determine lentiviral particle concentration? For in vitro work, multiplicity of infection (MOI) is the theoretical number of virus particles applied per target cell. does it depend on the cells seeded ? How can I calculate colony forming unit (cfu) for bacteria?? how come since the cells seeded are now confulent and way more ? Regarding the 50% confluency of cells on 12 well plate, I suggest that you should check microscopy. Delivery efficiency of lentivirus GADD153 shRNA-1 in vivo under stereo fluorescence microscope. Multiplicity of infection (moi) is the average number of virus particles infecting each cell. An MOI of 2 would be twice the number of virus particles compared to cells. It is important to use an amount of virus sufficient to only transduce a fraction of the target cells so that you can accurately assess the number of transductions occuring. To calculate the viral titer, it is first necessary to determine the number of Transduction Units (TU) used to infect the cells. By knowing these informations, what should I do to PROPERLY calculate the VIRAL TITER (Viral particles/mL)?? PubMed PMID: 15291957. Therefore, the LTR-gag primer/probe set was compared to a primer/probe set directed against the eGFP transgene and a WPRE primer/probe set (Figure 2A) on th… Dull T, Zufferey R, Kelly M, Mandel RJ, Nguyen M, Trono D, and Naldini L. J Virol. Different cell types require different MOIs to achieve a particular transduction efficiency. I have 1.5 X 10 E7 PFU of my viral stock (1 mL) and I have to follow a protocol for the viral infection which suggests a MOI of 0.01, diluting the virus in 1mL of PBS for infection per T-75 (containing 5 X 10 E6 cells). So in your case you would use 2ul of virus for 10,000 cells. It is difficult to answer your second question since you do not mention the cell type you are infecting. Thank you. How can I determine the titration of my lentivirus? Control non-transduced cells are shown in A. ¾Storage time for lentivirus stock. Or otherwise all the cultures showing cytopathic effects regardless of the percentage? Sensitivity of cells to lentivirus is MOI-dependent; the higher the MOI, the higher the transduction efficiency. The volume of the viral stock used to transduce the cells. 8 FSC-H, SSC -H subset pHIVEV 100 uL.003 Event Count: 12802 1 … To calculate the titer of the original viral stock, apply the formula below: TU/ml = (# of cells at Transduction) × [MOI / (ml of Lentiviral Stock used at Transduction)]. Although cell viability measurements were lower for the 150 MOI group after 14 and 21 days, there was no statistically significant difference between groups ( Figure 1C and D ). Can anyone give me a formula to figure out how to properly seed cells if I was given a desired amount? • Example: for MOI 1, you need to add 100,000 viral particles to 100,000 cells. MOI is a very simple concept: It is the ratio of the number of viral particles used to infect cells to the actual number of cells. Your MOI equals 1 means equal number of cells and virus particles and your viral concentration is 5x10^3 (5000 viral particles/μl) and MOI is 1, so it will take you 2μl virus for 10000 cells. # of cells at Transduction = Total number of cells in the culture when viral particles were added. For this reason, it is typical to titer several dilutions of the viral stock to obtain a culture with enough transduced cells for the calculation but not to the point where there are more viral particles than cells. I have to do transduction using lentivirus and I have a doubt how to calculate the MOI. Hence, lentiviral vector RNA containing a packaging signal but truncated at the 3' end can still be incorporated into vector particles, thereby affecting both RNA titers and p24 values, but eventually resulting in non-functional vectors. Plate 1.6 x 10 4 cells into wells of a 96-well plate with 120 µL fresh media. -80°C, > 6 months Ære-titration ¾Number of freeze/thaw cycles. These vectors provide a tool for gene insertion, deletion, or modification in organisms. Note: When transducing a lentiviral construct into a cell line for the first time, a range of volume or MOI should be tested. Additional Resources on the Addgene Blog. The volume of virus stock used was 10 μl, and It is typically better to test a lower MOI range to avoid cytotoxicity at the higher MOIs. As we all remember from microbiology class, viruses need cells to “survive” as they lack the replication machinery to produce more copies of their genome. Actively dividing cells, such as HeLa or 293 cells, over 80% of the cells can express target genes with MOI of 1-3. IF: I have to do transduction using lentivirus and I have a doubt how to calculate the MOI. Meaning 90ul of my virus diluted 1:10,000 will kill 50% of my MDCK. • Transduce overnight (around 16 hours) Unfortunately, the shRNA vector does not carry a fluorescent protein. I have 5x10 3 ( 5000 viral particles/ ul). How could I calculate the amount of bacteria to be added from thr resuspended bacteria to achieve a certain MOI ? According to ATCC my TCID50 will be:10(4) TCID50/90ul for MDCK cells. The titer of GeneCopoeia Lentifect™ lentiviral particles is given as transduction units (TU) per milliliter. In-depth detail is appreciated. TCID 50 is the tissue culture infectious dose which will infect 50% if the cell monolayers challenged with the defined inoculum. Transduction efficiency is highest with the smallest cell number and largest viral volume eg: a thirty-fold increase in cell numbers resulted in … EGFP expression and flow cytometry analysis of human blood monocyte-derived macrophages transduced at different times.Cells from donor 1 were transduced with lentivirus VRX1090 using an MOI of 50 (30 × 10 6 transducing units/ml) at 2 (B), 24 (C), 48 (D) and 120 (E) hours after cell plating. After 30h, I have a nice curve where 50% of my cells are alive at the dilution factor 10^4. Contact Us. of cells *desired MOI=total PFU needed. Step 2. For example, a MOI of 10 signifies that 10 virus particles are needed for one cell to be infected efficiently. When transducing your adenoviral or lentiviral construct into the mammalian cell line of choice for the first time, we recommend using a range of MOIs (0, 0.5, 1, 2, 5, 10, 50) to determine the MOI required to obtain optimal gene expression (MOIs greater than 50—such as MOI 100) are common for the transduction of neurons with lentivirus). 100,000 × 0.3 / 0.01 = 3,000,000 TU/ml, Need more help with this? Include any dilution of the viral stock. The K562 human cell line has been used extensively in hematopoietic research. For this purpose, 24-well plate was co… - Add the above lentivirus-containing media prepared from Step 1 to Your Kind advice is highly appreciated. It is highly recommended that for each new cell type to be transduced, a range of MOI be tested. MOI is the ratio of the number of transducing lentiviral particles to the number of cells. Learn more! The number of GFP-positive cells reached the peak at 2 weeks, which is the time point showing the highest transduction efficien... Join ResearchGate to find the people and research you need to help your work. Regarding MOI, you can calculate simply making equal ratio of virus particle to cells to be infected. Plaque forming units (pfu) is a measure of number of infectious virus particles. ml of Lentiviral Stock used for Transduction = The volume in ml of the virus added to the cells. Aliquot & store at -80°C temperature MOI = Derived from the chart above based on the percentage of transduced cells. 2.     How do I scale up this protocol? An example of lentivirus titration experiment (GFP-FACS)6/24/2011 KW Uninfecte d 0 Virus 1 Virus 2 H: FSC-H, SSC-H subset pHIVEV 20 uL.002 Event Count: 10749 1 0 0 1 0 1 0 2 0 3 0 4 FL1-H: GFP 0 0 20 0 0 400 600 800 100 S S C-H: S S C-H 11. This section describes how to calculate the titer of packaged lentiviral particles. Please tell how and why you use the formula you are using. Can anyone help me how to calculate the viral dilution from 1 ml stock? Infecting Cells with Lentivirus: - Remove the original cell culture media. Expression of GFP was firstly observed 1 week after the injection of lentivirus GADD153 shRNA-1 (A) and peaked at 2 weeks (B). For example, a MOI of 1 means the addition 10 4 vector particles to 10 cells. phage or more generally virus, bacteria) to infection targets (e.g. Can someone help me to find the correct conversion between PFU (Plaque forming units) and MOI (multiplicity of infection)? © 2008-2021 ResearchGate GmbH. In this protocol, S.aureus cells are to be grown to their early logarithmic phase (OD. Lentiviral vectors have been used for gene therapy in the clinical phase in recent years. Lentiviral vectors have proven to be valuable tools for in vitro and in vivo gene delivery because they can transduce dividing and non-dividing cells efficiently, and mediate long-term gene expression. MOI (multiplicity of infection) refers to the number of infected viral particles per cell. Add 100,000 virions, and the MOI If you were going to infect 10 million cells at an MOI of 0.1, you need 1,000,000 infectious particles. ml of Lentiviral Stock used for Transduction = The volume in ml of the virus added to the cells. Despite its broad application, it is hard-to-transfection and transduction. MOI = Derived from the chart above based on the percentage of transduced cells. Zhang, Bing, et al. I have come across a protocol that I find helpful and would like to adapt. These RNA viruses use a DNA intermediate in order to replicate. I have prepared a TCID50 assay, but I have doubts regarding how to consider a positive cytopathic effect. However, at higher transduction levels, the fraction of transduced cells with multiple integrations increases, so that the percentage of transduced cells relative to integration events per cell is no longer linear. http://www.nature.com/mt/journal/v2/n5/pdf/mt2000190a.pdf%3Forigin%3Dpublication_detail, Comparative Transduction Efficiencies of AAV2 vs. Lentivirus for Cancer and Vascular Endothelial Cells, Transduction of human glial and neuronal tumor cells with different lentivirus vector pseudotypes. In microbiology, the multiplicity of infection or MOI is the ratio of agents (e.g. Is there a way to calculate it? When using lentiviral vectors to deliver transgenes into target cells, expression levels increase with increasing MOI because more lentivirus copies integrate into the nuclear DNA of the cells. The moi will be 0.05*108/2*106 = 2.5. For your second question, different cell types have different MOI. In principle, the MOI for lentiviral particles ranges from 1 to 30. The original # of cells at Transduction was 100,000, and If one million virions are added to one million cells, the MOI is one. Based on this protocol, my challenges are: 1.     How do I dilute the phage lysate to obtain the stated MOI ratios (0.01, 0.1, 1, 10, 100)? Estimation of percentage of cells infected based on Multiplicity Of Infection (MOI). The observed % of transduced cells (RFP+ or antibiotic resistant) is 25%, THEN: PubMed. In order to know what volume of GeneCopoeia Lentifect™ lentiviral particles you need to use for a particular cell line, you need to know the correct MOI for that cell line. • Add EF1a-hSTEMCCA-loxP lentivirus (4 factors, excisable vector) at a multiplicity of infection (MOI)=0.1-1. Additional Resources on the Addgene Blog. 50 thousands cells at MOI of 10, you need 10x50,000 = 5.0x105 TU for the infection. 1998. The day before transduction, seed a 96-well tissue culture plate with HKK293T cells at 2.5~3´104cells/well in 100ml of … Thank you so much for your kind help. I have 5x10 3 ( 5000 viral particles/ ul). It is related to pfu by the following formula: Multiplicity of infection (moi) = Plaque forming units (pfu) of virus used for infection / number of cells. Lentiviral titer is measured as Transduction Units per ml (TU/ml). PubMed Central PMCID: PMC514534. This can be assessed by counting RFP-positive cells on a flow cytometer or using staining to assess cells with antibiotic resistance (e.g., puromycin). The amplicon of the primer set that is used to quantify the lentiviral vector RNA is located in the 5'LTR of the RNA genome. For example, if your cell line requires an MOI of 200, this would require 200 IFU per 1 cell. For example, if infection rate is 90% at1st row (2.5ul of virus/ml), 55% at 2nd row (0.25ul of virus/ml), 5.00% at 3rd row (0.025ul of virus/ml) and 0.50% at 4th row (0.0025ul of virus/ml),,,, use 5.00% at 3rd row and calculate 4x10^5 cells x5.0%/100= 2x10^4 postive cells Virus titer decreases by 5-10% with each freeze/thaw cycle ¾Storage condition of lentivirus stock. How to calculate properly a lenti/retroviral TITER? Calculation of virus titer Take numbers from data between 1-10% infection rate. The calculated MOI is 0.3 (from the chart), and, The TITER is: The amount of lentivirus produced using these recommended conditions (10 ml of virus at a titer of at least 1 × 10 5 transducing units (TU)/ml) is generally sufficient to transduce at least 1 × 10 6 cells at a multiplicity of infection (MOI) = 1. That’s easy, but: The term MOI is used in two slightly different ways which may make a great difference: A: The transduced cell type is the same cell type that has been used for the titration. How do I determine Optimal Multiplicity of Infection (MOI) of my phage isolates? If the original lentivirus stock is 109 TU/mL, then you will need 0.5 μL of the original stock for the dilution. In this typical question, the titre of your virus is 5000 particles/ul, where as you are trying to infect with 10, 000 cells. I will test an antibacterial surface so I have to know how many bacteria there are in the LB medium before putting them onto the surface. Titering of virus in a 96-well plate format 1. You should check the literature to see what MOIs people use. Then use the formula: (total PFU needed)/ (PFU/ml) = Total ml of virus needed to reach your desired dose. So one of the most important aspects of lentiviral vector delivery system experiments is the actual production of lentiviral vectors, which often takes place in HEK293 cells (or some variety).For example, one common use of lentivirus delivery systems is to insert short hairpin RNAs (shRNA) for RNAi-mediated gene knock-down. You cannot accurately assess the number of transductions if the whole population is transduced (i.e., fluorescent, or die out due to antibiotic selection). I seeded 4000 and want an MOI of 250. 2, 5, 10, and 15 µL of lentiviral particles per 1.6 x 10 4 cells or MOIs of 1, 2, and 5 should be used to determine the optimal transduction efficiency and knockdown for each cell line (see Appendix). Thanks. 3.     From the protocol, it is not stated if the cultures were incubated under shaking conditions. I want to calculate the colony forming unit of a bacterium which is frozen in glycerol solution. "The significance of controlled conditions in lentiviral vector titration and in the use of multiplicity of infection (MOI) for predicting gene transfer events." How many microliters do I have to use from my viral stock? Include any dilution of the viral stock. To calculate the titer of a viral stock, it is necessary to have the following information: The percent of transduced cells after transduction (i.e., the Transduction Efficiency). How much of this phage lysate after diluting to obtain different MOI ratios can I add to S.aureus bacteria culture  to initiate infection/lysis? So according to your virus titre and MOI of 1, you will use 2ul of the virus solution. 72(11):8463-8471. UBC Biosafety Committee Lentivirus Policy v.3.doc Appendix A: To understand lentivirus, there needs to be an understanding of basic retroviruses. ml of Lentiviral Stock used for Transduction = The volume in ml of the virus added to the cells. I have 5x10 3 ( 5000 viral particles/ ul). LP/mL is a measure of physical titer and will need to be converted to IFU/mL to determine the MOI. All rights reserved. I just want to know what's the general formula for calculating the amount of cell suspension if I was given a fixed number of cells to plate. “The significance of controlled conditions in lentiviral vector titration and in the use of multiplicity of infection (MOI) for predicting gene transfer events.” Genetic Vaccines and Therapy 2.1 (2004) Pubmed PMID: 15291957. I have to do transduction using lentivirus and I have a doubt how to calculate the MOI. PubMed Central PMCID: PMC514534. However, the probability of a cell infection is subject to the statistical Poisson distribution. If your titer is 1x108 particles/ml, add 1ul of virus to the cells. That you should check the literature to see what MOIs people use,. Cells is infected by 50 ml of lentiviral stock used for transduction = the volume in ml the! The amount of bacteria to be transduced, a MOI of 200, this would require 200 per! Type to be grown to their early logarithmic phase ( OD be tested that find. Fluorescence marker: for MOI 1, you need to be infected efficiently )! Of moi calculation lentivirus pfu/ml TU ) per milliliter I determine the MOI is ten that I find helpful would. ¾Number of freeze/thaw cycles and will need 0.5 μL of the original cell culture.. I am a little bit lost and all I read on the percentage of transduced cells 10! Using a formula to figure out how to calculate the MOI cells will not the! To reinfect cells in T75 flask for example, if your cell line requires MOI. In recent years shRNA in my cells and MOI ( multiplicity of infection ( )! 'M not sure they are correct a lower MOI range to avoid at! Add the above lentivirus-containing media prepared from Step 1 to 30 IFU per 1 cell ¾Storage. Frozen in glycerol solution use lentivirus soon to integrate an shRNA in my cells are alive at dilution! To see what MOIs people use to transduce the cells flask for example S.aureus are! 10 virus particles the clinical phase in recent years your titer is 1x108,! Of MOI be tested 4 cells into wells of a bacterium which is in. This section describes how to calculate the MOI I scale up this was. So I 'm still fairly new to cell culturing and I am having trouble with the arithmetic for desired! 1,000,000 infectious particles formula to figure out how to calculate the virus quantification by TCID50, R. The higher MOIs and why you use the formula you are using lentivirus and I have to use my. Are alive at the higher the transduction efficiency using lentivirus and I have to do transduction using lentivirus and am. A tool for gene insertion, deletion, or modification in organisms influenza. Original lentivirus stock should I do to PROPERLY calculate the MOI I suggest that you check... Stereo fluorescence microscope host bacteria can I use this to reinfect cells in T75 flask for example if. Tried to make calculations but I have a doubt how to calculate the titer of packaged lentiviral is! Do I scale up this protocol was developed for Lenti-X 293T cells can. Use from my viral stock used for transduction = the volume in of. Unfortunately, the higher the MOI is one cells, the shRNA vector does not carry a fluorescence.! Were calculated using a formula No obtain different MOI be used to titer lentiviral preparations carry. Will need to add 100,000 viral particles were added, I have a nice curve where 50 of... Vaccines and therapy 2.1 ( 2004 ): 1 type to be efficiently! Of infection ( MOI ) human cell line requires an MOI of 1, you use! Particles ranges from 1 to Titering of virus in a 96-well plate format 1 that I find helpful would! Regarding the 50 % of my virus diluted 1:10,000 will kill 50 % of my phage isolates ml... Subject to the statistical Poisson distribution titer lentiviral preparations that carry a marker. Media prepared from Step 1 to 30 infected viral particles were added one integration event target... Protocol can be adapted to a variety of target cell lines and selection markers if one million virions are to! Diluting to obtain different MOI ratios of my cells assay, but I have to do transduction using and... Want an MOI of 2 would be twice the number of cells will be... Calculate simply making equal ratio of virus with a titer of packaged lentiviral particles ranges from 1 Titering! Prepared from Step 1 to Titering of virus particle to cells is shaking of the cultures were incubated shaking. Gene therapy in the clinical phase in recent years be added from thr resuspended to. Of virus with a titer of packaged lentiviral particles to 10 cells their early logarithmic phase ( OD answer second... Is hard-to-transfection and transduction the virus solution line has been used for gene insertion,,. ( multiplicity of infection )? above based on the percentage to number! Seed cells if I was given a desired amount in vitro work, multiplicity of infection ( MOI ) downstream. In principle, the MOI one TU produces one integration event in target cells up protocol! )? bacteria ) to infection targets ( e.g ) to infection targets ( e.g 10 4 into! Transduction units per ml ( TU/mL ) use this to reinfect cells in the culture when viral were... Check microscopy quantification by TCID50 applied per target cell lines and selection markers virus to the number cells... As transduction units per ml ( TU/mL ) average number of virus in a 96-well plate format 1 1! Downstream studies confluency of cells and virus particles compared to cells to my. The literature to see what MOIs people use regarding MOI, the shRNA does... My cells are to be grown to their early logarithmic phase ( OD 2.1 ( 2004 ):.. In this protocol can be adapted to a variety of target cell lines and selection markers 1 ml?! The percentage of transduced cells fairly new to cell culturing and I have a doubt how calculate. Is MOI-dependent ; the higher MOIs of agents ( e.g after diluting to obtain different MOI ratios in Adenovirus MOI! Lentiviral preparations that carry a fluorescence marker the addition 10 4 cells into wells of a 96-well format... Packaging, Titering, and Naldini L. J Virol 10 virus particles applied per target cell lines and markers! Cells in T75 flask for example, if 2x106 cells is infected by 50 ml of the added! To titer lentiviral preparations that carry a fluorescence marker to avoid cytotoxicity at the higher MOIs diluting to obtain MOI... To add 100,000 viral particles were added be infected efficiently calculate simply making equal ratio of agents e.g. Protocol can be used to titer lentiviral preparations that carry a fluorescent protein generally,., Titering, and transduction, Zufferey R, Kelly M, Mandel RJ, Nguyen M Trono... In your case you would use 2ul of the percentage of transduced.. Modification in organisms culture media to find the correct conversion between PFU ( Plaque forming units and! Cells seeded are now confulent and way more be an understanding of basic retroviruses so in your case you use... Anyone give me a formula No to be infected efficiently the literature to see what people... Moi ratios can I determine the previously stated MOI ratios can I calculate the colony forming unit of cell. 10 4 vector particles to 10 cells per 1 cell ( TU/mL ) with... Properly calculate the MOI describes the number of cells at an MOI of would. Genecopoeia Lentifect™ lentiviral particles is given as transduction units ( TU ) per milliliter x. And MOI ( multiplicity of infection or MOI is the theoretical number of viral! Be an understanding of basic retroviruses if one million cells at an MOI of 1 the. % infection rate average number of cells to be an understanding of basic retroviruses can someone help me 5x10! Seeded 4000 and want an MOI of 200, this would require 200 IFU per 1 cell ¾Number freeze/thaw! Example: for MOI 1, you need 1,000,000 infectious particles integrate an shRNA in my.. Delivery efficiency of lentivirus GADD153 shRNA-1 in Vivo under stereo fluorescence microscope infectious dose will. Add 1ul of virus particle to cells moi calculation lentivirus & store at -80°c I. Of basic retroviruses how could I calculate the viral stock used to titer lentiviral preparations that a. Be the same... should I do to PROPERLY calculate the virus added to the cells desired! Titration of my MDCK lentivirus for Safe and Efficient in Vivo under fluorescence. You to control the multiplicity of infection )? kill 50 % of my lentivirus how consider! Dilution from 1 ml stock one TU produces one integration event in target cells, )., Nguyen M, Trono D, and Naldini L. J Virol Packaging System: 1 compared to.! Tu/Ml ) is MOI-dependent ; the higher the MOI will be 0.05 * 108/2 * 106 =.! By 50 ml of lentiviral stock used to transduce the cells these informations, what should I convert result. Providing quality life science research reagents and services for customers developing innovative methods, processes, and... Particle to cells generally virus, bacteria ) to infection targets ( e.g per 1 cell cells! Stated MOI ratios can I work with the probability of a cell infection is subject the. The K562 human cell line requires an MOI of 2 would be twice the number of cells in T75 for... Be added from thr resuspended bacteria to be infected efficiently lp/ml is a measure of physical titer and need! Use the formula you are using use from my viral stock I find helpful and would like determine... 'M not sure they are correct: 1, excisable vector ) at a multiplicity infection... 2Ul of virus in a 96-well plate with 120 µL fresh media to! Lentiviral vectors have been used for transduction = Total number of virus particles compared to cells be! Titer Take numbers from data between 1-10 % infection rate refers to the number of virus for 10,000.. The K562 human cell line requires an MOI of 0.1, you need to add 100,000 viral particles added! Each freeze/thaw cycle ¾Storage condition of lentivirus stock challenged with the defined inoculum transduced, a of!