My oligonucleotide does not appear to be the right length when I checked by gel electrophoresis. Why is this?
Oligos should be run on a polyacrylamide gel containing 7 M urea and loaded with a 50% formamide solution to avoid compressions and secondary structures. Oligos of the same length and different compositions can electrophorese differently. dC's migrate fastest, followed by dA's, dT's, and then dG's. Oligos containing N's tend to run as a blurry band and generally have a problem with secondary structure.
The primers I am using worked for PCR initially, but over time, have stopped working. What happened?
Primers should be aliquoted for single use before PCR set-up. Heat just the aliquoted primers to 94 degrees for 1 min. Quick chill the primer on ice before adding to the PCR reaction. Some primers may anneal to themselves or curl up on themselves.
I don't see a pellet in my oligo tube order. Should I ask for a replacement?
The drying method dries the primer in a thin layer along the sidewalls of the tube instead of the bottom, therefore a pellet is not always visible and should still be ready to use.
There is a ball-shaped pellet at the bottom of my oligo tube. What is this and can I still use my oligo?
If the oligo was overheated, it will appear as a ball-shaped pellet attached to the bottom of the tube. This should not affect the quality of the oligo, and the oligo should be readily soluble in water.
There is a green color in my lyophilized oligo. Can I still use it?
If an oligo appears green in color, this is most likely due to ink falling into the tube. The oligo should still be fully functional. The color can be removed by doing an ethanol precipitation.
p38 alpha mitogen-activated protein kinase is activated by CD28- mediated signaling and is required for IL-4 production by human CD4+CD45RO+ T cells and Th2 effector cells.
Authors:Schafer PH, Wadsworth SA, Wang L, Siekierka JJ
Journal:J Immunol
PubMed ID:10358155
'T cell proliferation and cytokine production usually require stimulation via both the TCR/CD3 complex and the CD28 costimulatory receptor. Using purified human CD4+ peripheral blood T cells, we show that CD28 stimulation alone activates p38 alpha mitogen-activated protein kinase (p38 alpha). Cell proliferation induced by CD28 stimulation alone, a response ... More
Allurin, a 21-kDa sperm chemoattractant from Xenopus egg jelly, is related to mammalian sperm-binding proteins.
Authors: Olson J H; Xiang X; Ziegert T; Kittelson A; Rawls A; Bieber A L; Chandler D E;
Journal:Proc Natl Acad Sci U S A
PubMed ID:11562501
Previously, we demonstrated that a protein from Xenopus egg jelly exhibits sperm chemoattractant activity when assayed by either video microscopy or by sperm passage across a porous filter. Here we describe the isolation and purification of allurin, the protein responsible for this activity. Freshly oviposited jellied eggs were soaked in ... More
Association of IL12B promoter polymorphism with severity of atopic and non-atopic asthma in children.
Background Severe asthma is a frequent cause of hospital admission, especially among children. The main environmental triggers of airway inflammation in asthma are viruses and aeroallergens. These agents elicit reciprocal immune responses, characterised by production of T helper 1 and T helper 2 cytokines, respectively. There is no genetic explanation ... More