2014 Journal Impact Factors have beed released. Please search: Impact Factor Search Engine
2013 SCI Journal Impact Factors were released recently. http://www.bioxbio.com/if/
Actually, these are the 2012 impact factors because the impact factors cannot be calculated until all of the 2012 publications have been processed by the indexing agency. The impact factors of each year were published in next year.
The 2012 impact factor of a journal was calculated as follows:
A = the number of times that articles published in that journal in 2010 and 2011, were cited by articles in indexed journals during 2012.
B = the total number of “citable items” published by that journal in 2010 and 2011. (“Citable items” are usually articles, reviews, proceedings, or notes; not editorials or letters to the editor.)
2012 impact factor = A/B.
Bacteria, Virus, Eukaryotes typical genome sizes:
Virus: 1 ~ 360 kb (mimivirus: 1.2 Mb )
Bacteria: 0.5 ~ 13 Mb
Eukaryotes: 8 Mb ~ 670 Gb
Largest genome known： Polychaos dubium (670 Gb)
Human genome size: around 3,200 Mb
E.coli genome size: 4,639,221 (E. coli K-12)
Fasta and Fastq are text-based formats for storing sequences. Parsing Fasta and Fastq is the routine work for bioinformatics researchers.
Kseq is a small and terse library for parsing the FASTA/FASTQ format. it can parse both FASTA and FASTQ format and even a mixture of FASTA and FASTQ records in one file.
Example command line for compiling a program using Kseq library:
gcc test.c -o test -lz
R2A Medium (R2A Agar) is a culture medium for culturing oligographic bacteria. It is usually use to count the bacteria in drinking water treatment and distribution systerms. Here is the R2A Agar recipe:
Proteose peptone 0.5g
Casamino acids 0.5 g
Yeast extract 0.5g
Soluble starch, 0.5g
Dipotassium phosphate 0.3g
Magnesium sulfate 7H2O 0.05g
Sodium pyruvate 0.3g
Final pH 7.2 ± 0.2 @ 25 °C
Add ddH2O to 1000ml
SOC (Super Optimal Broth) Medium is a nutrient-rich medium used for bacterial culture.
The following is SOC medium recipe for 1 L:
5g Yeast Extract
Add ddH2O to 1000ml
Adjust pH to 7.0~7.5 by adding concentrated sodium hydroxide (10N NaOH), autoclave to sterilize, add 20 ml of sterile 1 M glucose immediately before use.
Similar with TAE Buffer, TBE is also a buffer commonly used in molecular biology experimets.
5X TBE Buffer Recipe:
53 g of Tris base
27.5 g of boric acid
20 ml of 0.5 M EDTA(pH 8.0)
Add ddH2O to 1 Liter
When using, dilute the stock solution by 5x in ddH2O. (For example, adding 200ml 50X TAE Buffer to 800ml ddH2O)
Although 10X TBE Buffer can also be make as the stock solution, it much more likely precipitate than TAE. So, 5x is a better choice.
50X Stock Solution of TAE Buffer:
Tris base: 242g
Glacial Acetic Acid: 57.1ml
0.5 M EDTA: 100ml
Add ddH2O to 1 Liter and adjust pH to 8.5 using KOH.
1X Working Solution of TAE
1X working solution of TAE buffer is made by simply diluting the stock solution by 50x in ddH2O. (For example, adding 20ml 50X TAE Buffer to 980ml ddH2O.
See Also: TBE Buffer Recipe
High throughput sequencing platform, namely the second generation sequencing can produce thousands or millions of sequences in a short time with a relative low cost. Now it was widely used in metagenomic sequencing and other biological field. Currently, there are mainly 3 high throughput sequencing platform:
1. 454 pyrosequencing
GS FLX Titanium
2. Illumina (Solexa) sequencing
Illumina HiSeq 2000
3. SOLiD sequencing
The SOLiD™ System
The concontrations of DNA and RNA can be calculated by measuring their optical density (OD260), and the purity of these nucleic acids can be estimated by the ratio of OD260 to OD280. The following is a Nucleic Acids Calculator, The concentrations of dsDNA, ssDNA, RNA, ssOligo can be calculated easily.