Stain Technique No

Stain Technique No. 1 (Feldspars, Quartz, and Calcite). Chemicals needed in this procedure are concentrated HF (52%), a 5% barium chloride solution in distilled water, a saturated solution of sodium cobaltinitrite, and a solution of amaranth (28 grams of F.D. and C. Red No. 2 pure coal tar dye in 2 liters of water). Amaranth is also called Azorubin S, C. 1.16185, available from Polysciences, Inc., in Warrington, Pennsylvania, and other chemical supply houses. This stain is primarily for silicates, but may include clay minerals when aggregated in shale particles. Testing with the shale, as such, will define the usefulness of the stain in this regard. 

Sieve the crushed raw materials to produce a 45-to 125-pm fraction and a fraction greater than 125-pm, or other intervals as you wish. Study of the stained 45-pm insoluble residue is particularly informative. An alcohol or water wash cleans the sieve fractions by removing the very fine par-tides held electrostatically. 

Under a ventilating hood, spread the particles on the flat bottom of a small 100 mL Teflon beaker. Place the container on a plastic support within a larger Teflon beaker (400 mL), the bottom of which has been covered with HF acid to a depth of approximately 3 to 4 mm. Cover the larger container to trap the HF vapors and leave the sample therein for approximately two (2) minutes. Because this technique requires the use ofHF 

Remove the container with the particles from the acid vapors and, with a small pipette, cover the particles with the sodium cobaltinitrite solution for two (2) minutes. 

Withdraw the cobaltinitrite solution with a paper towel and wash the particles into a watch glass or suitable beaker with a stream of distilled water from a squeeze bottle, quickly withdrawing the rinse water with a paper towel or decanting. Repeat the rinse procedure and withdraw the water with a towel. 

---

Stain Technique No. 2 (Evamy Stain for Calcite, Ferroan Dolomite, and Ankeiite). Chemicals needed for this method are one (1) gram of alizarin red S mixed with five (5) grams of potassium ferricyanide in distilled water, containing two (2) ml of concentrated HCl. The solution is brought to one (1) liter with distilled water and stored in a dark container. The raw feed can be sieved as described above. 

Stain Technique No. 3 (Dolomite). This stain has been found to be applicable to raw feed particles as well as thin sections. 

Texas Red hydrazide is a derivative of Texas Red sulfonyl chloride made by reaction with hydrazine (Invitrogen). The result is a sulfonyl hydrazine group on the No. 5 carbon position of the lower-ring structure of sulforhodamine 101. The intense Texas Red fluorophore has a QY that is inherently higher than either the tetramethylrhodamine or Lissamine rhodamine B derivatives of the basic rhodamine molecule. Texas Red s luminescence is shifted maximally into the red region of the spectrum, and its emission peak only minimally overlaps with that of fluorescein. This makes derivatives of this fluorescent probe among the best choices of labels for use in double-staining techniques. 

Kapp et al. (1979) reported the presence of Y-chromosomal non-disjunction in 1,2-dibromo-3-chloropropane-cxposed workers using a quinacrine-staining technique. [There was no indication of the level of exposure to 1,2-dibromo-3-chloropropane or whether other exposures were present.] The frequency of sperm with two spots (indicating two Y chromosomes) was 1.2% (range, 0.8-1.8%) in 15 controls and 3.8% (range, 2.0-5.3%) in 18 samples from exposed men. 

The specificity of the NADPH diaphorase staining technique for NOS is dependent on aldehyde fixation. For unknown reasons, the NADPH diaphorase activity of NOS is resistant to fixation, whereas the NADPH diaphorase activity of other NADPH-requiring enzymes in the brain is destroyed by aldehydes (14). Fixation in 4% paraformaldehyde for 4 h at 4°C should provide sufficient fixation for small pieces of tissue (<0.5 cm ). Longer fixation times or fixation at room temperature should be used if the staining observed appears nonspecific (i e., if all of the tissue stains purple)... 

Histochemical studies by Swift [31] have indicated that within the nucleus there are three main sites that contain RNA the spindle, the chromosomes, and the nucleolus. Spindle RNA can be demonstrated with histochemical techniques during telophase and early interphase. This type of RNA is usually close to the chromosome, but has no immediate connection with that structure. Swift has developed a staining technique that allows the experimenter to distinguish between... 

Staining of polymers is an important part of sample preparation for electron microscopy as it provides the enhanced contrast required to image the structures. There are few staining techniques that work for a range of polymers and there are several stains with limited applicability. For many polymers there is no proven stain, and thus preparative treatments must be found by experimentation. This sunnnary will provide a listing (Tables 4.1-4.3) of those polymers which have been shown to be stained by the various reagents described in this section. In addition, several stains that are applicable for only a few polymers are also listed here, even though they were not fully described. 

As far as the choice of a suitable staining technique for peroxidase detection is concerned, it must again be pointed out that guaiacol and pyrogallol are at least as reliable as any other donors and avoid errors due to the presence of HjOa in the test solutions. It is much more difficult to avoid the interference from oxidase action, however, in whole cells than in solution. No reliable methods are known to the authors that would allow a sharp discrimination between oxidase and peroxidase activities in vivo. A discussion of possible techniques for assaying peroxidase in the presence of oxidases will be given at the end of this paper. 

---