High-tech breakthrough DNA scanner for reading sequence and detecting gene mutation. A powerful 1 lb, 20 micron resolution, 16-bit personal scanner (PS) that scans 17" x 14" X-ray film in 48 s, with laser, UV and white light sources.

The 17" x 14" X-ray film, gels, and blots are widely used in DNA research. However, DNA laser scanners are costly and unaffordable for the majority of surveyed biotech scientists who need it. The high-tech breakthrough analytical personal scanner (PS) presented in this report is an inexpensive 1 lb hand-held scanner priced at 2-4% of the bulky and costly 30-95 lb conventional laser scanners. This PS scanner is affordable from an operation budget and biotechnologists, who originate most science breakthroughs, can acquire it to enhance their speed, accuracy, and productivity. Compared to conventional laser scanners that are currently available only through hard-to-get capital-equipment budgets, the new PS scanner offers improved spatial resolution of 20 microns, higher speed (scan up to 17" x 14" molecular X-ray film in 48 s), 1-32,768 gray levels (16-bits), student routines, versatility, and, most important, affordability. Its programs image the film, read DNA sequences automatically, and detect gene mutation. In parallel to the wide laboratory use of PC computers instead of mainframes, this PS scanner might become an integral part of a PC-PS powerful and cost-effective system where the PS performs the digital imaging and the PC acts on the data.

Crystallin mRNA product levels in lens undergoing reversal and inhibition of galactose cataracts.

In our previous work, two-dimensional gel electrophoretic analysis of the translational products from mRNA of lens from rats maintained on 50% galactose up to 45 days has suggested that synthesis of mRNA was not arrested by the disease process, but it decreased significantly relative to the control. The loss in mRNA number was due mainly to loss in cell population. Specifically, the gamma-crystallin mRNA product decreased to very low levels at onset of the disease. However, this mRNA was resynthesized in the surviving cells as the cataracts matured. Therefore, it became of interest to explore whether reversal or inhibition of cataracts would lead to some measurable changes in mRNA population in the experimental lens. The results show that the percentage (relative to the total mRNA population) of the in vitro [35S]-labeled translational products from alpha-, beta- and gamma-crystallin mRNAs combined, remained unchanged irrespective of the state of the lens. The severity of the cataracts was examined by indirect immunofluorescence with polyclonal MP26 antibody. Reversal of cataracts led to partial recovery of normal fiber cell morphology. Treatment with sorbinil in combination with galactose led to inhibition of cataracts with indication of appearance of vacuoles at longer periods of exposure to the drug. The translational products profile reflected the expected variation in non-crystallin and crystallin mRNA synthesis. It is concluded that there appears to be a combined fixed level of synthesis for the crystallins, such that inhibition in synthesis of gamma-crystallin mRNAs appears to lead to an increase in synthesis of alpha-crystallin mRNAs, while synthesis of beta-crystallin mRNAs showed insignificant fluctuation. A similar conclusion may also be drawn relative to the combined synthesis for the non-crystallin mRNAs.

Soft-laser scanning densitometry performed on a 35-mm slide illustrating SDS-PAGE separation of adenovirion polypeptides.

Virion polypeptides (35 S), methionine-labeled and purified by CsCl gradient centrifugation, were separated by SDS-gel electrophoresis. Analysis of their band pattern was performed by scanning the images of the SDS-gels shown on a 35-mm slide. The densitometric tracings revealed the presence of 17 protein bands, although only 15 of them were visible to the naked eye. The high sensitivity and resolving capacities of the soft-laser scanning densitometer enabled us to detect trace amounts of protein bands separated in SDS-gels and to obtain a resolution compatible to that of electrophoresis. Fourfold electronic amplification of the densitometric tracings, produced by a computer, generated new information regarding the pattern of the electrophoregram. The facility to amplify peaks of importance is particularly advantageous when faint or overlapping protein bands revealed on a gel are assessed.

Use of reflectance in soft laser densitometry in scanning opaque electrophoregrams. A high-resolution technique.

The present report describes a new approach in soft laser scanning densitometry performed on opaque electrophoregrams. The method employs a light reflectance system instead of absorption, which is commonly used. The data of this preliminary study were obtained by directly scanning a photograph of an electrophoregram exhibiting viral proteins separated by SDS-PAGE. Comparison of the two methods clearly demonstrate that laser reflectance offers finer resolution than laser absorbance when opaque materials are scanned.

The metabolism of transferrin in burned patients.

The metabolism of transferrin was studied in 17 selected burned patients. Transferrin metabolism also was studied in 5 of the patients after healing. The concentration of plasma transferrin in burned patients, measured by radial immunodiffusion, was reduced to 300 mg% for the first week following injury. Thereafter it rose steadily reaching the normal concentration of 350-360 mg% 35 days after injury. Traces of transferrin were present in urine a week after injury. Transferrin was labeled by injecting 14C-glucosamine intravenously following injury and again after healing was complete. Labeled transferrin was isolated from serum by specific immunoprecipitation. The specific activity of transferrin reached a peak 3-6 hr after injury and 9-12 hr after healing. The half-life time was 4.5 days during injury and 9.6 days after healing. The data indicated that both synthesis and catabolism of transferrin were accelerated in injury.

Measurement of radial immunodiffusion plates with a scanning densitometer.

Measurement of the diameters of the precipitation rings in radial immunodiffusion plates with a scanning densitometer is described. Data obtained by scanning were compared with a conventional visual method of measurement and although the differences were statistically significant, the differences were small and there was no basis for determining which method was a more accurate estimation of concentration. It was concluded that the scanning method, which uses equipment present in most clinical pathology laboratories, is an acceptable alternative method for measuring radial immunodiffusion.

Chromatographic differences in serum amylase among species.

Chromatographic analysis of amylase in human, dog, rabbit, rat and chicken sera were performed and species differences recorded. Iodide, rather than chloride, requirement for optimal activity was demonstrated for one amylase fraction separated from rabbit sera.

Core isoelectrofocusing.

An improved method of isoelectrofocusing is described. A plastic rod is centered in a tube and the lumen is filled with gel. After separation the rod is withdrawn and replaced by staining solution. Staining and destaining are quick and simple. The gel remains stabilized in the tube allowing no distortion or breakage and permitting accurate localization of separated bands.