Rapid Process Mounting

Posted on June 8, 2014 by vade mecum microscope

Sorry for the lack of updates, the summer is always a less leisurely time than one expects. -K

When last macerated and pressed mounts were mentioned the method employed required a long weekend at a minimum, but the entire process can be done in a day. Some people will appreciate progressing from specimen collection to finished slide so rapidly and some are sure to prefer the day by day process of a longer method. For the summer months when both specimen availability and social obligations are at a peak, the following entries from my notes may prove welcome. Embellishments not appearing in my notes but provided here for clarity appear in parenthesis:

8 Jun. ’14 10:00am Captured 5 spiders from under the addition. Collected them into stoppered test tubes finding it easier than Mason jars (a flat of small jelly jars often makes up my collecting kit when working in the garden). Three of the spiders are larger and of orange hue which leads me to identify them as males of the common house spider. Two despite being smaller I take as females of the same species. (The description in the Audubon field guide describing males as orange and smaller than females, while Comstock elaborates at the striking variety of forms exhibited by the species and its tendency for differing specimens to be taken for differing species by novices. The habitat and cohabitating species contribute to my identification.)

Killed them by introducing Ether soaked cotton swabs to the test tubes. One stopper was ejected by the expanding gas and I feel a better poison will need to be collected (for use with this method I imagine chloroform will prove superior and more desirable than for instance, ethyl acetate, as speed is a factor).

11:18am Have processed the three males through to the pressing jar. Each was boiled in 3ml of 10% NaOH until quite transparent. (The test tubes into which the spiders were initially collected were used and heated over an alcohol burner. When doing so the test tube should be slightly tilted to face away from the preparer and towards bare floor or table to minimize danger in the case of bumping. Agitating the test tube slightly and holding over rather than in the flame will also help to prevent bumping.) The solution was then drawn off and aprox(imately) twice the volume of distilled water added to the test tube. Into this was placed several drops of glacial acetic acid until diffusion currents were no longer observed. The solution was then poured off and replaced w(i)t(h) aprox(imately) 2ml of distilled water.with a rubber stopper inserted the specimen was swirled in the tube until near the mouth and then rolled to be on the side away from the water adherent to the side of the tube. With the stopper removed the tube was manipulated so as to wash the specimen into a Syracuse glass.

(Here in my notes is a sketch depicting the motions required to carry the spider from the test tube with such a small amount of water. It is of course simpler to simply employ a larger volume of water but then it requires a larger Syracuse and in the end more potential for spillage. The ease of adding a sketch to handwritten notes is reason enough for me to never adopt an electronic medium for note taking.)

The females were placed into a Syracuse in the vacuum desiccator together with a jar of Drierite to await processing after the males are completed. (I try to work with specimens of a single type only at one time for the sake of simplicity. It’s far easier than one might expect to mix things up when working with only five specimens.)

(After a lite lunch with my wife, which gave the alcohol sufficient time to harden and dehydrate the specimens, I returned.)

1:50pm Removed pressed males and transfered them through to clove oil one by one. Find the first macerated to be a bit to opaque and hope the clearer will improve its appearance. All removed intact and came away from pressing slips without incident. (I use slips of the cheapest sort for pressing and some are never quite clean enough-or smooth enough-to release the specimens without damage. The cheap slips is a compromise I make for budgetary reasons as the spring clips which I use to hold the pressing slips together can be quite hard on the slips.)

2:45pm Mounted the males on plain beveled edge slips from Ted Pella in balsam under 22×35 Gold Seal covers. (I quite like the plain economy slips from Ted Pella, the beveled edges decrease immensely the tendency of chips to form when used on spring loaded mechanical stages.) One specimen became far off center and the cover was lifted and the specimen repositioned under a new glass, a leg was separated in the process but was left in approximately proper posit(ion). (Misplacement of specimens can be upsetting but unless it approaches the edge of the cover should be overlooked as the risk of damage is quite large once the balsam has begun to penetrate the specimen. I properly should have placed the whole into xylene to dissolve the balsam and then remounted as normal but with several specimens on hand I become less careful than I should be.)

3:12pm Slides placed in attic to cure. (If more rapid curing is required a cool oven or hot plate on very low setting can set the mountant nicely in a few hours. I prefer the heat of the attic of my home during summer as the hot [32-35C] dry [below 5% RH] attic cures slowly enough to permit even the largest and deepest air bubbles time to escape.)

Slide Catalogs, Indices, and Labels II

Posted on February 19, 2014 by vade mecum microscope

Time for another exciting bit of truly important tedium! -K

Part Two; Catalog and Index
From the previous post it should be clear that the form of label can vary wildly as can the information on it. Its hardly possible to fit all of the useful information one might have concerning a specimen, or its treatment, on a slides labels. Logically the thing to do is place the more extensive information in a secondary location where it is both accessible and organized: a catalog or database of some kind is warranted.

The information kept may be standardized across an entire collection or it may vary and be tailored to each slide depending on what is relevant or known. The decision on whether to maintain a constant or variable set of information is as much a mater of preference as the choice of what to include on the slides label. Information may be spartan and limited only to that which not obvious, or robust in the extreme filling an entire sheet of paper.

This raises an other question, the choice of medium on which to compose the catalog. One can compose the catalog on traditional media such as looseleaf paper kept in a binder, or a series of index cards in a file. The variety of digital options is quite extensive, specialized software will prove popular with some while a simple spreadsheet or web based database might be preferable for some hobbyists. For particularly large or complex collections a digital catalog can prove expedient if for no other reason than its being rapidly searchable and previous entries are more easily updated or expanded. A hard copy catalog of printed forms filled in by hand with ink is often simpler to use in practice.

Papers recommending the form which a slide catalog can take and the information one should include date to the nineteenth century and may be found in any number of texts. Guides on the subject are not infrequently written for slides produced for a particular study or by a specific laboratory; what is required of a catalog for one series of slides may differ substantially from an other. Few recommendations exist concerning the catalog kept by an amateur and such a catalog faces all the challenges of a curators catalog and more.

Specimens may be of enormously different sorts and of massively divergent ages. The knowledge the cataloger posses of each slide may be likewise variable. If one relies on a catalog where the information recored is constant regardless of slide, there is a substantial risk that many fields will necessarily be left black for slides which are purchased as opposed to slides which are prepared by ones self or vice versa. One may side step such a pitfall by using only broad information in ones catalog and providing a section where particular notes unique to each slide may be entered.

An index of some sort if useful simply for providing ready access to the information of a desired slide, or type of slide. With a digital catalog a traditional index is largely superfluous as the rapid searching provided by the software used should negate the need for a formal index. For a paper catalog one may organize the index around a handful of useful information, such as the specimens name, or the type of preparation. It is a simple manner to adapt a printed address book and make entries alphabetically which correspond to numbers in the catalog proper or pages of the catalog. One may also use the index to locate slides if entries within it point to the location where the slide is stored. If at first such an index seems more labor than it is worth when a substantial number of slides are had it will prove useful, particularly for the aid of collections that are used by others than the curator.

Whatever manner of catalog is kept, in whatever form, it is undeniably of great utility particularly when one begins preparing or collecting permanent mounts. If one simply tucks slides into cases as they are acquired it will become all to easy to lose track of a delightful preparation just when it is most needed. A catalog serves to fix a means of organization as much as a method of retaining information that will not fit upon a slides label. I have no wish or standing to set a best program for the creation of a slide catalog but as with labels I will attempt some broad standards that will help inspire one who wishes to compose a useful catalog.

Each entry should bear a number that corresponds to an indelible mark on the slide to which it corresponds.
Each entry should inform upon the location of the slide in storage, i.e. Box A, Slot 1 etc.
Each entry should inform upon the provenance of the slide.
Each entry should identify the preparation by the name that is marked on the label of the slide to which it corresponds.
Each entry should include both the common name of the specimen and its scientific name if known.
Each entry should identify the source of the specimen; point of collection if known, limited to type if unknown i.e. whole mount, transverse section, smear etc.
Each entry should describe in general terms the process used in preparation if known.
Each entry should include the mountant used.
Each entry should include the date of mounting if known, the date of acquisition is unknown.
Each entry should inform as to the gauge of coverslip used.
Each entry should include a section for notes of interest not provided for elsewhere in the catalog.

Next post will be about mounting a specimen or two, I promise!

Slide Catalogs, Indices, and Labels

Posted on February 14, 2014 by vade mecum microscope

When building up a collection of slides it’s not uncommon for the collector to simply put them up in a case without a thought to organization or logging. It’s too bad considering the tools available to keeping track of things. Labels are an old tool but still of value. -K

Part One; Labels

I’m old enough to remember with apprehension the advent of digital catalog systems. I remember when looking for “that article about you know, the new study” in a journal whos name wasn’t remembered meant hoping the librarian knew your field at best, and wading through a cross index compiled by some other librarian at some other library and hoping a name seemed familiar at worst. Digital cataloging and inexpensive terminals changed all that. It became possible to dispense with a wall of tiny drawers and an army of clerks pounding away at typewriters loaded with cream colored cards. Keeping records became faster with the digital revolution, at least as far as looking things up went.

Putting records into the system, whatever system, is still time consuming. In place of typewriters there are keyboards and in place of cards there are fields on a database program. Of course keeping records can be faster now but it still requires some time and thought. What has any of this to do with microscopy? Slides of course. The cataloging used in libraries is rather similar to that needed for keeping slides organized so it’s only fitting that the two might be compared. Books however, have a bit of a leg up on the average microscope slide; there are pages within a book dedicated to identifying it. Slides have their labels, ideally, but often they are nearly useless for the sake of brevity.

Oh AmScope what horror is next?

The record keeping associated with the utility of a microscope slide is often overlooked. It’s tragic that the modern supply houses putting out their cookie-cutter slides, however well made and nicely stained, tend to put next to nothing on their labels. The nearest thing to a catalog is usually a printed card with only the name of the specimen and maybe a number corresponding to a slot in the case. One can see an example of this sort of modern prepared collection above. It is simple, mass produced, dubious in quality (notice specimen 2, Coprimus? because of course they can’t expect an underpaid technician to know that Coprinus is a genus and Coprimus is gibberish) but inexpensive and readily available.

When purchasing antique slides the collectors knowledge of the mounter or the uniqueness of the specimen, even the artistry of the preparation makes up for the usual absence of any extra notes. It’s noteworthy though to consider the differences in the labels on a modern slide and one of significant age. Below are two slides, each from a recognizable firm but of significantly different age. The primary market of each company varied as well. The more contemporary company markets almost entirely to young students and their teachers, the older served professionals, and amateur enthusiasts of every age.

One of these things…

On the more modern slide the information provided is rather limited to say the least. It is labeled “Bacteria Types w.m. Ba 020 Carolina Biological Supply Company”. Certainly knowing it is a slide of whole mount (w.m.) bacteria would permit one to look in the right text for identification but there is plenty of space on the label so it wouldn’t have been impossible to put the type of bacteria on the slide itself. Knowing the company and seeing their own catalog reference (Ba 020) would make it a bit easier to track down more information about the specimen but not knowing a date and considering the recent changes at Carolina finding out anything further about the slide will be difficult. As an example of different bacteria types the slide is useful, but as a representative specimen it is quite useless without a good deal of effort.

The older slide is from W. Watson & Sons and also has rather limited information on it’s labels. However, the quality of that information is entirely more useful because the mounter knew the intended use of the slide. The slide is a test slide, made of a known object under rather exacting conditions so that it may be used to test the quality of a particular objective. One can see that the specimen is of Pleurosigma angulatum and that it is mounted in Styrax. Knowing the mountant is necessary for test objects (or any specimen) because without it (or more specifically the refractive index of it) one can not measure the thickness of the specimen accurately. Electron microscopy has largely eliminated the arguments concerning the actually form of a spring-tails scale but an objectives ability to resolve one is a classic measure of quality.

…is not like the other.

Above one can see two more slides, of an entirely different sort than the previous two. On the left is a blood smear from a Hematology laboratory while on the right are two serial sections of primate brain from a research laboratory. One has a pasted on label which has a coating of balsam, while the other is marked in ink on its frosted end. One has only cryptic markings that are seemingly useless without a knowledge of the specimen and the logging practices of the lab, the other is clearly marked, immediately recognizable and identifiable without additional information. Neither has any information about the specimen preparation or treatment, neither has a date, neither informs on the mounter or the mountant.

On the slide to the right one can see that a printed label reading “Clarkson Hospital Laboratory” has had “Chronic Lymphatic Leukemia” typewritten on it. One may find that Clarkson Hospital is likely Bishop Clarkson Memorial Hospital once of 415 South 26th St. Omaha Nebraska which closed it’s doors and merged with University Hospital in 1997. From the appearance of the label and by virtue of digging into the history of Clarkson one could date the slide to the 1950’s without to much trouble. The characteristic color of the smear makes it rather simple to guess the stain employed and a hematology text of appropriate vintage might even provide information on the preparation method, but it would only be a guess. A textbook with color photomicrographs would likely replace the function of this slide in a modern hospital but as an example of the condition it depicts it is still useful.

The slide on the left reads only what looks like “511 GABA 1:1000 C8 Elilè”. Cryptic to say the least, but the specimen is clearly a section of brain. From its size and morphology one might easily guess it is of a small animal, likely a primate. Looking about for a connection between the markings on the label and primates one can find reference to gamma-Aminobutyric acid (GABA) receptors in the field of neurophysiology without too much effort. The first number is no doubt a catalog or subject reference, I can only guess at what the ratio might be in reference to but it’s not much of a leap to hypothesize that “C8” is a reference to order of the sections. Being in possession of a second slide labeled the same but for “C9” makes such a guess a near certainty. If I had a subscription to the Journal of Neurophysiology, and sufficient interest, I might be able to identify what the marking in red actually reads or likely indicates. An interesting slide, but even with a more comprehensive label it would remain little more than an interesting object of little utility outside the laboratory where it was produced.

It’s worth noting that the contents of a label change depending on the intended use of a slide as much as they do depending on the time period during which it was produced. Whatever information is placed upon a label is useful, but the use to which that information is put might vary wildly. When one prepares their own slides the only limit on the information on the label is what one imposes for ones self. In the various texts available all sorts of claims are made as to the necessary information a label must have. One can see from the above that this information has never become standardized, nor is it ever likely to become so. Labels then are almost exclusively in the realm of preference, yet permit a few exceedingly general suggestions:

One should provide a slide with a label the contents of which are useful to the mounter and the intended audience.
One should provide a slide with a label which will endure the conditions of use and storage.
One should put their name on each slide they prepare.
One should put the date of mounting on each slide.
One should include some method of referencing more extensive information than the space on the label permits.

Be sure to tune in next time for more exceedingly boring walls of text dealing only in a cursory way with microscopy!