Substitutes for Ethyl Alcohol

Three substitute solvents were investigated as substitutes for ethanol in nine commonly used staining fluids. Anhydrous methanol (“Bioloid” grade, Will Corporation) was found an entirely satisfactory substitute in these fluids, and isopropanol only slightly inferior.     

The Plastic Ethyl Methacrylate in Routine Laboratory Technic

The use of ethyl methacrylate as a permanent, transparent, colorless medium for mounting in toto invertebrate and vertebrate embryos and small adults is demonstrated.

The liquid monomer is partially polymerized by heating over a hot-plate, the reaction being aided by the use of benzoyl peroxide as a catalyst. The object to be mounted is fixed, stained, dehydrated, and cleared in the usual manner, and is then infiltrated with the partially polymerized ethyl methacrylate. It is oriented on a hardened base in a glass or porcelain dish, and the mold is then allowed to harden (polymerize) completely at a temperature of 38-40° C. under a 250-watt infra-red, ultra-violet bulb. After the block is removed from the dish it may be polished by the ordinary metallurgical methods. More than 40 species of animals have been satisfactorily treated in this manner.     

Comparison of Macroscopic Examination, Routine Gram Stains, and Routine Subcultures in the Initial Detection of Positive Blood Cultures

Blood was cultured in two vaccum bottles containing Columbia broth with sodium polyanethol sulfonate and CO₂. Filtered air was admitted to one bottle, and the bottles were incubated at 35 C until growth was detected or for a maximum of 7 days. Bottles were examined daily for macroscopic growth. Gram stains were made routinely on the 1st, 4th, and 7th days, and samples were routinely subcultured to sheep blood agar (incubated in GasPak jar) and chocolate agar (incubated in CO₂) on the 1st and 4th days of incubation. Of 1,127 positive blood cultures, 65% were first detected by macroscopic examination, 23% were first detected by Gram stain, and 12% were first detected only by subculture.     

Laboratory Identification of Torulopsis glabrata: Typical Appearance on Routine Bacteriological Media

The colonial morphology of the yeast Torulopsis glabrata on sheep blood-agar is characteristic and was useful in the identification of 24% of clinical isolates.     

A Method for Compiling Bacteriological Findings in a Medium-Sized Hospital

A method for classifying and compiling bacteriological findings has been established in a 350-bed hospital in order to allow future correlation of laboratory data with information obtained from clinical observations. All information available before and after bacteriological investigation was registered by notching the appropriate holes of a 5 × 8 McBee Keysort perforated card. Each hole on the card corresponded to a specific item of information such as wards, type of specimens, sensitivity to antibiotics and sulfonamides, bacterial species, and so on. With this method it is easy to pick out with a needle any information that may be requested, for example: (1) incidence of Staphylococcus pyogenes in specimens submitted by each department, (2) Staphylococcus pyogenes strains isolated in each department, (3) antibiotic sensitivity patterns, and (4) incidence of cultures yielding positive growth.     

醋酸氯己定与乙醇的协同杀菌效果

采用悬液定量杀菌试验,对醋酸氯己定与乙醇的协同杀菌效果进行了实验室研究。研究发现,0.1%醋酸氯己定与75%乙醇混合溶液对金黄色葡萄球菌、大肠埃希菌、白假丝酵母菌和黑曲霉均呈现出显著的协同杀菌作用。结果表明,醋酸氯己定与乙醇具有良好的协同杀菌效果。     

Hematoxylin Substitutes: A Survey of Mordant Dyes Tested and Consideration of the Relation of Their Structure to Performance as Nuclear Stains

In the search for hematoxylin substitutes 26 dyes were more or less extensively tested for performance as nuclear stains, usually in combination with aluminum, chromic, ferrous and ferric salts. Reports from the literature on hematoxylin substitutes were also considered, and efforts were made to obtain samples of favorably reported dyes and test them. The reports on anthocyanins include isolated reports on several berry juices and a considerable number of studies on Sambucus niger and Vaccinium mytillus. None of these have so far been tested by us. Otherwise favorable reports have appeared on eleven synthetic dyes and on carmine, brazilin, and hematein. Except for one of the synthetics, naphthazarin, which is no longer manufactured, we had samples of all of these. In addition, more or less unsuccessful trials were made on twelve dyestuffs, some of which were new syntheses designed to combine chelating capacity with nucleophilia. Following Fyg's report of blue nuclear staining with chrome alum carmine, trial was made to change the red nuclear stain of kernechtrot by altering the metal mordant.

The most successful dyes were phenocyanin TC, gallein, fluorone black, alizarin cyanin BB and alizarin blue S. Celestin blue B with an iron mordant is quite successful if properly handled to prevent gelling of solutions.     

Progress in the Standardization of Stains Certain Less Commonly Used Stains

The Commission must acknowledge the assistance recently given by two commercial concerns in developing two new products, namely, a pure type of hematein and a special grade of acid fuchsin.