![Now, let’s calculate the log2 fold change: log2_mean_clusterB - log2_mean_other_cluster #> [1] 5.638924. So, it seems Seurat updated their calculation method to add a small value of 10^-9 rather than 1. This is almost the same as the FindAllMarkers results… percentage of cells that are positive of CD19 in B cells and other cells:. Tote gote](/img/512x512/1418605907708.webp)
Jan 30, 2021 · 1.78K subscribers. Subscribed. 188. 28K views 3 years ago. Subscribe for a fun approach to learning lab techniques: / @adwoabiotech A fold change is simply a ratio. It measures the number of... Spread the loveFold change is a widely used method to represent the differences in gene expression levels between two or more samples. It measures the ratio of the final value to the initial value, simplifying the data interpretation process. This article will guide you through the steps to calculate fold change. Step 1: Understand the Data Before calculating fold change, ensure you have ...Mar 9, 2018 ... ... Real time PCR Data? | Real Time PCR Gene Expression Fold Change Calculation. Learn Innovatively with Me•65K views · 19:43. Go to channel ...In your case, if a 1.5 fold change is the threshold, then up regulated genes have a ratio of 0.58, and down regulated genes have a ratio of -0.58. As it says in the linked article, log transformed fold changes are nicer to work with because the transform is symmetric for reciprocals. That means, log2(X) = -1 * log2(1/x), so it is much easier to ... Step 1. Divide the new amount of an item by the original amount to determine the fold change for an increase. For instance, if you have 2 armadillos in a hutch and after breeding, you have 8 armadillos, the calculation is 8/2 = 4. The 4 means that you have a 4-fold increase in the number of armadillos. Video of the Day. 11-03-2010, 01:13 PM. you should be careful of these genes. In my points, you do not need calculate the fold change. You can split these cases into two situations: one condition is larger or smaller than threshold, e.g. gene RPKM>=5 (one Nature paper uses this scale). For the smaller, it is nothing, while the larger is significant different.Sep 18, 2020 · This logarithmic transformation permits the fold-change variable to be modeled on the entire real space. Typically, the log of fold change uses base 2. We retain this conventional approach and thus use base 2 in our method. The 0.5’s in the numerator and denominator are intended to avoid extreme observations when taking the log transformation. Fold change converted to a logarithmic scale (log fold change, log2 fold change) is sometimes denoted as logFC. In many cases, the base is 2. Examples of Fold Change / logFC. For example, if the average expression level is 100 in the control group and 200 in the treatment group, the fold change is 2, and the logFC is 1.But, should the mean fold-change be calculated as (1) a mean for all individual fold-changes of all the subjects or rather (2) a ratio of mean 2^-dCt(target gene) and mean 2^-dCt(reference gene ...Dividing the new amount. A fold change in quantity is calculated by dividing the new amount of an item by its original amount. The calculation is 8/2 = 4 if you have 2 armadillos in a hutch and after breeding, you have 8 armadillos. This means that there was a 4-fold increase in the number of armadillos (rather than an actual multiplication). Dividing the new amount. A fold change in quantity is calculated by dividing the new amount of an item by its original amount. The calculation is 8/2 = 4 if you have 2 armadillos in a hutch and after breeding, you have 8 armadillos. This means that there was a 4-fold increase in the number of armadillos (rather than an actual multiplication). To calculate the fractional (fold) or percent change from column B to column A, try linking built-in analyses: Copy column B to column C. Create column D containing all zeros. Do a "Remove baseline" analysis, choosing to subtract column B from column A and column D from column C. This produces a results sheet with two columns: A-B and B.The relative change from 75 to 25 is -0.6667 or -66.67%.To calculate this manually, follow these steps: Subtract the initial value from the final value to get their difference: Δx = 25 − 75 = -50.. Divide this difference by the absolute value of the initial value to get the relative change: Relative change = -50/|75| = -0.6667.. Multiply this …To select the differentially expressed (DE) genes in a microarray dataset with two biological conditions, the Fold Change (FC) which is calculated as a ratio of averages from control and test sample values was initially used [1, 2].Levels of change or cutoffs, (e.g. 0.5 for down- and 2 for up-regulated) are used and genes under/above thresholds …Then calculate the fold change between the groups (control vs. ketogenic diet). hint: log2(ratio) ##transform our data into log2 base. rat = log2(rat) #calculate the mean of each gene per control group control = apply(rat[,1:6], 1, mean) #calcuate the mean of each gene per test group test = apply(rat[, 7:11], 1, mean) #confirming that we have a ...To calculate the logarithm in base 2, you probably need a calculator. However, if you know the result of the natural logarithm or the base 10 logarithm of the same argument, you can follow these easy steps to find the result. For a number x: Find the result of either log10(x) or ln(x). ln(2) = 0.693147.Figure 4 illustrates another advantage of the paired design over the unpaired designs in our CRC study, beyond statistical power. When a simple fold change threshold is considered, the paired design tends to result in greater fold changes, in the sense that a higher proportion of genes will have fold changes above a given threshold in the paired …Good eye akrun. I think I misinterpreted what I actually need to calculate which is just fold change, NOT log2 fold change. I will now edit my question to reflect this, but of course my gtools code of "logratio2foldchange" is innacurate and the other gtools requires an input of foldchange(num, denom), which I currently do not have my df set up as.The log2 fold change can be calculated using the following formula: log2 (fold change) = log2 (expression value in condition A) - log2 (expression value in condition B) where condition A and ...Yes, you can use the second one for volcano plots, but it might help to understand what it's implying. The difference between these formulas is in the mean calculation. The following equations are identical:The Himalayas, Alps, Andes and Appalachian Mountains are examples of fold mountains. The Jura Mountains in Switzerland and France and the Zagros Mountains in Iran and Iraq are also...Fold change = ppm of sample 1 / ppm of sample 2. Log fold change = Log (Fold change) = Log (ppm 1) - Log (ppm 2) Log fold change normally means Log base 10 (Log10). This provides an order-of ... 1. Calculate your mean Ct value (N>/=3) for your GOI in your treated and untreated cDNA samples and equivalent mean Ct values for your housekeeper in treated and untreated samples. 2. Normalise ... When it comes to hosting a special event or even just sprucing up your everyday dining experience, paying attention to the smallest details can make a big impact. One such detail t...At this point to get the true fold change, we take the log base 2 of this value to even out the scales of up regulated and down regulated genes. Otherwise upregulated has a scale of 1-infinity while down regulated has a scale of 0-1. Once you have your fold changes, you can then look into the genes that seem the most interesting based on this data.A comparison of the 5 μg and 20 μg sample lanes indicates a 3.1-fold increase in signal, lower than the predicted 4-fold increase. Comparison of the 10 μg and 30 μg sample lanes indicates a larger discrepancy in band intensity: a 1.6-fold increase is observed, roughly half of the expected 3-fold change.Apr 29, 2024 · How to Use the Calculator: Input Values: Enter the initial value and final value into the respective fields of the calculator. Calculate Fold Change: Click the "Calculate Fold Change" button to obtain the fold change ratio. Interpretation: The calculated fold change represents the magnitude of change between the two values, providing insight ... So, if you want to calculate a log2 fold change, it is possible to keep this log2-transformation into account or to discard it. What I mean with this is that the mean of logged values is lower than the mean of. the unlogged values. Take for example the series: 2, 3, and 4. > log2(mean(c(2^2, 2^3, 2^4))) > [1] 3.222392. >.In today’s fast-paced world, privacy has become an essential aspect of our lives. Whether it’s in our homes, offices, or public spaces, having the ability to control the level of p... 1. Calculate your mean Ct value (N>/=3) for your GOI in your treated and untreated cDNA samples and equivalent mean Ct values for your housekeeper in treated and untreated samples. 2. Normalise ... 5. Calculate the fold gene expression values. Finally, to work out the fold gene expression we need to do 2 to the power of negative ∆∆Ct (i.e. the values which have just been created). The formula for this can be found below. Fold gene expression = 2^-(∆∆Ct) For example, to calculate the fold gene expression for the Treated 1 sample:Revision: 23. Volcano plots are commonly used to display the results of RNA-seq or other omics experiments. A volcano plot is a type of scatterplot that shows statistical significance (P value) versus magnitude of change (fold change). It enables quick visual identification of genes with large fold changes that are also statistically significant.There are 5 main steps in calculating the Log2 fold change: Assume n total cells. * Calculate the total number of UMIs in each cell. counts_per_cell: n values. * Calculate a size factor for each cell by dividing the cell's total UMI count by the median of those n counts_per_cell.Proteomics studies generate tables with thousands of entries. A significant component of being a proteomics scientist is the ability to process these tables to identify regulated proteins. Many bioinformatics tools are freely available for the community, some of which within reach for scientists with limitedTo calculate the fractional (fold) or percent change from column B to column A, try linking built-in analyses: Copy column B to column C. Create column D containing all zeros. Do a "Remove baseline" analysis, choosing to subtract column B from column A and column D from column C. This produces a results sheet with two columns: A-B and B.The log fold change is then the difference between the log mean control and log mean treatment values. By use of grouping by the protein accession we can then use mutate to create new variables that calculate the mean values and then calculate the log_fc .I calculated the Fold Change for each sample (and then the mean FC) and my result was presented as "On average, neoplastic cells expressed this gene 1.25x (+25%) the control group".Aug 17, 2023 · The Percentage Change Calculator (% change calculator) quantifies the change from one number to another and expresses the change as an increase or decrease. This is a % change calculator. Going from 10 apples to 20 apples is a 100% increase (change) in the number of apples. This calculator is used when there is an “old” and “new” number ... It is best to calculate the mean ± s.d. for each group as individual data points using. ... The fold change in expression between the treated and untreated mice is: 0.120/4.31 = 0.0278; fold ...Aug 18, 2021 ... Data File used for demonstration: [Data File ...Fold change is calculated as 2^ (-ΔΔC T) – in other words, it doubles with every reduction of a single cycle in ΔC T values. This may or may not be the exact fold …Here I want to calculate (as part of a bigger function) the fold-change of placing the tree in a sunny place compared to a dark one within each combination of fertilization amount and type of tree(e.g. a 2-fold change for lightly fertilized apple trees):Calculate Z-Fold Panels. Enter the flat size width in inches: Click this button to calculate the panel sizes: Panel 1, 2, & 3: 4-Panel Roll-fold. A 4-Panel Roll Fold has 4-panels per side for a total of 8-panels. Two panels are the same size, while panels 3 & 4 are one-eigth and one-quarter of an inch shorter in width respectively.Vector of cell names belonging to group 2. mean.fxn. Function to use for fold change or average difference calculation. fc.name. Name of the fold change, average difference, or custom function column in the output data.frame. features. Features to calculate fold change for. If NULL, use all features. slot.Owning a home is wonderful. There’s so much more you can do with it than you can do with a rental. You can own pets, renovate, mount things to the wall, paint and make many other d...(character) The level name of the group used in the denominator (where possible) when computing fold change. The default is character(0). method (character) Fold change method. Allowed values are limited to the following: "geometric": A log transform is applied before using group means to calculate fold change. In the non …Table 10.2 Worked Example to Calculate Fold Change (Ratio) Using Cq Differences. This is a very simple example of a study with the requirement to measure the fold difference between one gene in two samples and after normalization to a single reference gene. The ratio shows the fold change of the GOI in sample 2 relative to sample 1, after ...Fold-change-specific GO terms were occasionally detected in animal transcriptomes as well, e.g., very weak but significant activation of immunity-related processes have been shown in . However, the role of fold-change-specific transcriptional response has not been studied systematically, because there were no ready-to-use …Updated February 17, 2024. Show Your Love: The Fold Difference Calculator is a mathematical tool design to calculate the fold change between two values. This calculation is pivotal in fields such as biology, finance, and data analysis, where understanding the magnitude of change is crucial.Fold change: For a given comparison, a positive fold change value indicates an increase of expression, while a negative fold change indicates a decrease in expression. This value …log2 fold change values (eg 1 or 2 or 3) can be converted to fold changes by taking 2^1 or 2^2 or 2^3 = 1 or 4 or 8. You can interpret fold changes as follows: if there is a two fold increase...The threshold must be set in the linear phase of the amplification plot in Figure 1C. The C t value increases with a decreasing amount of template. However, artifacts from the reaction mix or instrument that change the fluorescence measurements associated with the C t calculation will result in template-independent changes to the C t value.Calculate log2 fold-change and mean expression for the data. log2_fold_change <- log2 (untrt_sample_means) - log2 (trt_sample_means) mean_expression <- ( log2 (untrt_sample_means) + log2 (trt_sample_means)) / 2The output data tables consisting of log 2 fold change for each gene as well as corresponding P values are shown in Tables E2–E4. It can be helpful to generate an MA plot in which the log 2 fold change for each gene is plotted against the average log 2 counts per million, because this allows for the visual assessment of the distribution of ...So, I want to manually calculate log2 fold change values from DESeq2 normalized counts. So, I am using log2 (DESeq2norm_exp+0.5)-log2 (DESeq2norm_control+0.5) for calculating log2 fold change values. I am not sure whether it is a good idea or the choice of pseudo-count here is very critical. The other option I guess is performing VST on raw counts.To convert between fold amounts and percentages, we calculate: Percentage = 100 ÷ Fold Number. Some examples: Five-fold increase = 100/5 = 20% increase. Ten-fold improvement = 100/10 = 10% better. Two-fold growth = 100/2 = 50% more. Conversely, we calculate: Fold Increase = 100 / Percentage. 20% increase = 100/20 = Five-fold.val = rnorm(30000)) I want to create a data.frame that for each id in each group in each family, calculates the fold-change between its mean val and the mean val s of all other id s from that group and family. Here's what I'm doing now but I'm looking for a faster implementation, which can probably be achieved with dplyr: ids <- paste0("i",1:100)Out of curiosity I have been playing with several ways to calculate fold changes and I am trying to find the fastest and the most elegant way to do that (hoping that would also be the same solution). The kind of matrix I am interested in would look like this:Fold change is calculated simply as the ratio of the difference between final value and the initial value over the original value. Thus, if the initial value is A and final value is B,...Fold Change Calculator. Nuc-End-Remover. Seq Format Converter. Sequence Counter. Sequence Trimmer.To convert between fold amounts and percentages, we calculate: Percentage = 100 ÷ Fold Number. Some examples: Five-fold increase = 100/5 = 20% increase. Ten …To convert between fold amounts and percentages, we calculate: Percentage = 100 ÷ Fold Number. Some examples: Five-fold increase = 100/5 = 20% increase. Ten-fold improvement = 100/10 = 10% better. Two-fold growth = 100/2 = 50% more. Conversely, we calculate: Fold Increase = 100 / Percentage. 20% increase = 100/20 = Five-fold.The Fold Increase Calculator is a valuable tool used in various scientific and analytical fields, such as molecular biology, genomics, and data analysis, to quantify the relative increase or change in values, often expressed in multiples or “folds.” This calculator is particularly useful when comparing data sets, such as gene expression ...This logarithmic transformation permits the fold-change variable to be modeled on the entire real space. Typically, the log of fold change uses base 2. We retain this conventional approach and thus use base 2 in our method. The 0.5’s in the numerator and denominator are intended to avoid extreme observations when taking the log transformation.The log fold change is then the difference between the log mean control and log mean treatment values. By use of grouping by the protein accession we can then use mutate to create new variables that calculate the mean values and then calculate the log_fc .@Zineb CuffDiff do calculate log2 fold changes (look at the output file gene_exp.diff and iso_exp.diff). Btw CuffDiff adds a pseudocount in the order of ~0.0001 FPKM). With regards to baySeq if ...Feb 17, 2024 · The Fold Difference Calculator is a mathematical tool design to calculate the fold change between two values. This calculation is pivotal in fields such as biology, finance, and data analysis, where understanding the magnitude of change is crucial. The predictive log fold changes are calculated as the posterior mean log fold changes in the empirical Bayes hierarchical model. We call them predictive log fold changes because they are the best prediction of what the log fold change will be for each gene in a comparable future experiment. The log fold changes are shrunk towards zero depending ...11-03-2010, 01:13 PM. you should be careful of these genes. In my points, you do not need calculate the fold change. You can split these cases into two situations: one condition is larger or smaller than threshold, e.g. gene RPKM>=5 (one Nature paper uses this scale). For the smaller, it is nothing, while the larger is significant different.Figure 4 illustrates another advantage of the paired design over the unpaired designs in our CRC study, beyond statistical power. When a simple fold change threshold is considered, the paired design tends to result in greater fold changes, in the sense that a higher proportion of genes will have fold changes above a given threshold in the paired …If you’re looking to stay fit and healthy, investing in a treadmill can be a great idea. Treadmills provide the convenience of exercising from the comfort of your own home while al...If you are still unsure, an easy way to convert the primer efficiency percentage is to divide the percentage by 100 and add 1. For this example, I will pretend I have calculated the primer efficiency of my GOI as ‘ 1.93 ‘ (93%) and the HKG as ‘ 2.01 ‘ (101%). 2. Average your technical replicates.You can now identify the most up-regulated or down-regulated genes by considering an absolute fold change above a chosen cutoff. For example, a cutoff of 1 in log2 scale yields the list of genes that are up-regulated with a 2 fold change. Get. % find up-regulated genes. up = diffTableLocalSig.Log2FoldChange > 1;(iv) Fold-change versus normalized mean counts . MA plots are commonly used to represent log fold-change versus mean expression between two treatments (Figure 4). This is visually displayed as a scatter plot with base-2 log fold-change along the y-axis and normalized mean expression along the x-axis.For a particular gene, a log2 fold change of -1 for condition treated vs untreated means that the treatment induces a multiplicative change in observed gene expression level of \(2^{-1} = 0.5\) compared to the untreated condition. If the variable of interest is continuous-valued, then the reported log2 fold change is per unit of change of that ...Aug 29, 2006 · Those genes appearing on the lower left region or the lower right region have a large fold-change and a larger P-value, such as Gene 1810 having a fold-change of 2.97 with P-value of 0.01265 (see ... Sep 18, 2020 · This logarithmic transformation permits the fold-change variable to be modeled on the entire real space. Typically, the log of fold change uses base 2. We retain this conventional approach and thus use base 2 in our method. The 0.5’s in the numerator and denominator are intended to avoid extreme observations when taking the log transformation. In today’s fast-paced world, maximizing space has become a top priority for many homeowners. One innovative solution that has gained popularity in recent years is the California Cl...One of these 17 groups was used as the control, and the log2 fold changes were calculated for the analyte concentration of each sample in each group using the average control concentration for that analyte. However, now I would like to calculate a p-value for the identified fold changes if possible. My current preliminary idea is to perform the ...When you travel abroad, you have to change the way you think about a lot of things. Stores may open later. People may line up differently. Restaurants may charge you for a glass of...To calculate percent change, we need to: Take the difference between the starting value and the final value. Divide by the absolute value of the starting value. Multiply the result by 100. Or use Omni's percent change calculator! 🙂. As you can see, it's not hard to calculate percent change.val = rnorm(30000)) I want to create a data.frame that for each id in each group in each family, calculates the fold-change between its mean val and the mean val s of all other id s from that group and family. Here's what I'm doing now but I'm looking for a faster implementation, which can probably be achieved with dplyr: ids <- paste0("i",1:100)Aug 17, 2023 ... Learn how to calculate percentage change between two values. Positive change is percent increase and negative change is a decrease.Here I want to calculate (as part of a bigger function) the fold-change of placing the tree in a sunny place compared to a dark one within each combination of fertilization amount and type of tree(e.g. a 2-fold change for lightly fertilized apple trees): To calculate fold change in Excel, input your data in two columns: one for gene expression before labor and another for during labor. Create a third column for fold change results. In the first cell of this column, enter the formula =B2/A2 to divide the expression during labor by the expression before labor. Fold mountains form when the edges of two tectonic plates push against each other. This can occur at the boundary of an oceanic plate and a continental plate or at the boundary of ...Revision: 23. Volcano plots are commonly used to display the results of RNA-seq or other omics experiments. A volcano plot is a type of scatterplot that shows statistical significance (P value) versus …One of these 17 groups was used as the control, and the log2 fold changes were calculated for the analyte concentration of each sample in each group using the average control concentration for that analyte. However, now I would like to calculate a p-value for the identified fold changes if possible. My current preliminary idea is to perform the ...Vector of cell names belonging to group 2. mean.fxn. Function to use for fold change or average difference calculation. fc.name. Name of the fold change, average difference, or custom function column in the output data.frame. features. Features to calculate fold change for. If NULL, use all features. slot.Fold change: For a given comparison, a positive fold change value indicates an increase of expression, while a negative fold change indicates a decrease in expression. This value … At this point to get the true fold change, we take the log base 2 of this value to even out the scales of up regulated and down regulated genes. Otherwise upregulated has a scale of 1-infinity while down regulated has a scale of 0-1. Once you have your fold changes, you can then look into the genes that seem the most interesting based on this data. Fold change: For a given comparison, a positive fold change value indicates an increase of expression, while a negative fold change indicates a decrease in expression. This value …
Fold change is calculated simply as the ratio of the difference between final value and the initial value over the original value. Thus, if the initial value is A and final value is B,.... Dulle trimble jefferson city obituaries
Service Offering: Bioinformatic Fold Change Analysis Service. Criteria: Set your fold-change threshold to dictate marker inclusion in positive or negative fold-change sets. Your chosen threshold must be greater than or equal to zero. Sample Requirements: Our precision-driven analysis mandates specific data inputs, ensuring accuracy and relevance. Calculate fold change. Hi, I am trying to calculate the fold change in expression of several hundred genes. If the fold change from my control condition to my experimental condition is greater or equal to 1 then there is no problem, but if the gene expression is lowered, i.e. less than one, I would like the cells to display the negative reciprocal.Divide the new amount of an item by the original amount to determine the fold change for an increase. For instance, if you have 2 armadillos in a hutch and after breeding, you have 8 armadillos, the calculation is 8/2 = 4. The 4 means that you have a 4-fold increase in the number of armadillos. A fold change is basically a ratio.2. The log fold change can be small, but the Hurdle p-value small and significant when the sign of the discrete and continuous model components are discordant so that the marginal log fold change cancels out. The large sample sizes present in many single cell experiments also means that there is substantial power to detect even small …The fold change model presented in this paper considers both the absolute expression level and fold change of every gene across the entire range of observed absolute expressions. In addition, the concept of increased variation in lowly expressed genes is incorporated into the selection model through the higher fold change …For a particular gene, a log2 fold change of -1 for condition treated vs untreated means that the treatment induces a multiplicative change in observed gene expression level of \(2^{-1} = 0.5\) compared to the untreated condition. If the variable of interest is continuous-valued, then the reported log2 fold change is per unit of change of that ...Revision: 23. Volcano plots are commonly used to display the results of RNA-seq or other omics experiments. A volcano plot is a type of scatterplot that shows statistical significance (P value) versus magnitude of change (fold change). It enables quick visual identification of genes with large fold changes that are also statistically significant.To calculate the logarithm in base 2, you probably need a calculator. However, if you know the result of the natural logarithm or the base 10 logarithm of the same argument, you can follow these easy steps to find the result. For a number x: Find the result of either log10(x) or ln(x). ln(2) = 0.693147.To calculate fold change (ie, divide vector by vector) we can use outer function. Here we are asking to divide vector V1 by vector V1 within data.table dfM by each group and family combination.You can interpret fold changes as follows: if there is a two fold increase (fold change=2, Log2FC=1) between A and B, then A is twice as big as B (or A is 200% of B). …Fold enrichment. Fold enrichment presents ChIP results relative to the negative (IgG) sample, in other words the signal over background. The negative sample is given a value of ‘1‘ and everything else will then be a fold change of this negative sample. As opposed to the percentage of input analysis, the fold enrichment does not require an ...#rnaseq #logfc #excel In this video, I have explained how we can calculate FC, log2FC, Pvalue, Padjusted and find Up/down regulated and significant and non...The relative change from 75 to 25 is -0.6667 or -66.67%.To calculate this manually, follow these steps: Subtract the initial value from the final value to get their difference: Δx = 25 − 75 = -50.. Divide this difference by the absolute value of the initial value to get the relative change: Relative change = -50/|75| = -0.6667.. Multiply this …The threshold must be set in the linear phase of the amplification plot in Figure 1C. The C t value increases with a decreasing amount of template. However, artifacts from the reaction mix or instrument that change the fluorescence measurements associated with the C t calculation will result in template-independent changes to the C t value.To analyze relative changes in gene expression (fold change) I used the 2-ΔΔCT Method. For the untreated cells i calculated 1. (control --> no change --> ΔΔCT equals zero and 2^0equals one) I ...Feb 5, 2022 ... Gene ontology : GO and KEGG enrichment analysis | shiny GO · qRT PCR calculation for beginners delta delta Ct method in Excel | Relative fold ...You need to calculate the value of 2 ^ {-\Delta\Delta C_ {t}} to get the expression fold change. What Does the Value Mean?11-03-2010, 01:13 PM. you should be careful of these genes. In my points, you do not need calculate the fold change. You can split these cases into two situations: one condition is larger or smaller than threshold, e.g. gene RPKM>=5 (one Nature paper uses this scale). For the smaller, it is nothing, while the larger is significant different..