Analysis of DNA Fragmentation Using Agarose Gel Electrophoresis Shailaja Kasibhatla et al. This protocol provides a qualitative method for assessing cell death by detecting DNA fragments using agarose gel electrophoresis. One of the classic features of apoptosis is the cleavage of the genomic DNA into oligonucleosomal fragments represented by multiples of 180-200 bp. Visualizing these fragments can aid in characterizing an apoptotic event. May be combined with more quantitative methods. - [Read Analysis of DNA Fragmentation Using Agarose Gel Electrophoresis (Subscription Required)]
Analysis of DNA Fragmentation Using the JAM Assay. By Shailaja Kasibhatla et al., The JAM assay is based on labeling nuclear DNA of cycling cells with [3H]thymidine and harvesting samples on glass fiber filters. Apoptosis will generate DNA fragments small enough to pass through the glass fiber filter, resulting in decreased radioactivity of the particular sample. Cell-mediated cytotoxicity or cell killing mediated by cytotoxic T lymphocytes (CTL) can also be measured by this technique. - [Read Analysis Of DNA Fragmentation Using The JAM Assay (Subscription Required)]
Detection of Phosphatidylserine Externalization During Apoptosis. Shailaja Kasibhatla et al. An early event in apoptosis is the externalization of phosphatidylserine (PS), a phospholipid normally restricted to the inner leaflet of the plasma membrane. This apoptotic event can be monitored using Annexin V, a PS-specific binding protein. This protocol uses Annexin V-FITC as a probe, but Annexin V-biotin is also available, and binding can be revealed using streptavidin-FITC or oth - [Read Detection Of Phosphatidylserine Externalization During Apoptosis (Subscription Required)]
DNA Affinity Chromatography, DNA affinity chromatography can be a low-tech method using gravity flow at 4°C, a disposable chromatography column, and DNA affinity resin prepared in the laboratory (see Preparation of a DNA Affinity Column). Include 10-20% glycerol and 0.025-0.1% NP-40 in the column buffers to suppress losses due to nonspecific adsorption of protein to surfaces. Load the protein in a buffer that is compatible with binding of the protein to its target site. Keith Brocklehurst et al - [Read DNA Affinity Chromatography Using Gravity Flow - Subscription Required]
This protocol describes the preparation of concatamerized oligonucleotides and their coupling to cyanogen-bromide-activated Sepharose. The procedure uses a commercially activated resin, which can be purchased as a lyophilized powder. Keith Brocklehurst et al. - [Read Preparation of DNA Affinity Resin - Subscription Required]
When many RNA samples are to be processed or when working with small amounts (<50 µg) of total mammalian RNA, the technique of choice is batch chromatography on oligo(dT)-cellulose. The method described in this protocol uses a combination of temperature and ionic strength to maximize binding and recovery of polyadenylated RNA. IMPORTANT: Prepare all reagents used in this protocol with Diethyl pyrocarbonate (DEPC)-treated H2O. Joseph Sambrook and David W. Russell. - [Read Selection of Poly(A)+ RNA by Batch Chromatography - Subscription Required]
Chromatography on oligo(dT) columns is the preferred method for large-scale purification (>25 µg) of poly(A)+ RNA extracted from mammalian cells. Typically, between 1% and 10% of the RNA applied to the oligo(dT) column is recovered as poly(A)+ RNA. Because the method can be frustratingly slow, it is not recommended for purification of poly(A)+ RNA from multiple samples. For this purpose, batch elution (Selection of Poly(A)+ RNA by Batch Chromatography) is the better choice. - [Read Selection of Poly(A)+ RNA by Oligo(dT)-Cellulose Chromatography - Subscription Required]