1、Designation: E 788 97 (Reapproved 2003)Standard Specification forPipet, Blood Diluting1This standard is issued under the fixed designation E 788; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers requirements for glass reusablebloo
3、d diluting pipets that are used for performing red and whitecell corpuscle determinations.2. Referenced Documents2.1 ASTM Standards:E 694 Specification for Volumetric Ware2E 920 Specification for Commercially Packaged LaboratoryApparatus2E 921 Specification for Export Packaged Laboratory Appa-ratus2
4、E 1133 Practice for Performance Testing of Packaged Labo-ratory Apparatus for United States Government Procure-ments2E 1157 Specification for Sampling and Testing of ReusableLaboratory Glassware23. Classification3.1 This specification covers two different pipet designs andpermissible alternatives.3.
5、1.1 Red and white cell blood diluting pipets (see Fig. 1).3.1.2 Permissible alternative designs (see Fig. 2).4. Materials4.1 The pipets shall be made of common spirit bore whiteback tubing or clear glass with a white stripe applied to theouter surface of the tubing.4.2 The beads shall be made of gla
6、ss or ceramic composi-tion and shall be of red, clear, or white coloring.5. Dimensions and Permissible Variations5.1 DesignThe red and white cell blood dilution pipetsshall consist of a small uniform bore glass tube which shallhave a bulb of proper size near the proximal end (see Fig. 1).As an alter
7、native, the pipets may be constructed of three piecesof glass that are fused together to form a one-piece pipet (seeFig. 2). The bulb shall contain a nonspherical glass or ceramicbead sufficiently large enough to prevent its being impacted inthe constriction portion of the bulb. The cross section of
8、 thepipet at any point shall be circular. The distal end of the whitecell pipet shall be pulled to a point and then ground andpolished to a tapered tip. The distal end of the red cell pipetshall be ground and polished to a tapered tip. The insidediameter (ID) of the pipet bore at the tip end of the
9、white cellpipet shall be 0.2 to 0.5 mm. The external diameter of theground and polished tip shall not exceed 2.0 mm. The overalllength of both pipets shall be 104 to 121 mm. The proximal endmay be of funnel design, with an exterior taper, or ground andpolished with a taper of sufficient angle to per
10、mit application ofa rubber suction tube or other suction device (see Fig. 2).5.2 CapacityThe capacity of the red cell pipet bulb shallbe 0.8 to 1.2 cm3and the capacity of the white cell bulb shall be0.2 to 0.4 cm3. The capacity of the red cell pipet stem (bulb todistal end) shall be 0.008 to 0.012 c
11、m3and the capacity of thewhite cell pipet stem shall be 0.02 to 0.04 cm3.5.3 Capacity Markings:5.3.1 Pipet Bulb MarkingsThe red and white cell pipetbulb capacity shall be confined to and indicated by calibrationlines on the pipet. These lines shall be located on both sides ofthe bulb and shall be wi
12、thin 2 mm to 6 mm above the bulb(proximal end) and within 3 mm to 6 mm below the bulb (distalend). The exact manner for measuring these line placements isspecified in Fig. 1.5.3.2 Pipet Stem MarkingsThe graduation lines on thestem of the red and white cell pipets shall be equally dividedinto two or
13、ten divisions. If there are two divisions, the twocalibration lines on the stem will be numbered 0.5 and 1. Ifthere are ten divisions, the ten calibration lines will benumbered 0.5 on the fifth line and 1 on the tenth linerespectively. The top line (above bulb at the proximal end)shall be numbered 1
14、01 on the red cell pipet and 11 on the whitecell pipet, representing stem and bulb volume collectively. Atthe option of the manufacturer, pipet stems may be graduatedwith split lines or partial length lines (see Fig. 2).1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory
15、 Apparatus and is the direct responsibility of Subcommittee E41.01 onGlass Apparatus.Current edition approved Nov. 10, 1997. Published February 1998. Originallypublished as E 788 81. Last previous edition E 788 93.2Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harb
16、or Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 Graduation LinesAll graduation lines on the red andwhite cell pipets shall be at right angles to the pipet axis andparallel to each other. The thickness of the graduation linesshall not exceed 0.4 mm.5.5 AccuracyThe red and w
17、hite cell pipet bulb volumeshall be a volumetric ratio to the stem volume. The red cellpipet bulb to stem ratio shall be 100:1 and the white cell pipetbulb to stem ratio shall be 10:1 when tested in accordance with6.1 and 6.2.5.6 Workmanship:5.6.1 The pipets shall be free of defects that detract fro
18、mtheir appearance or impair their serviceability.5.6.2 Construction shall be such that the mechanicalstrength is provided to withstand the rigors of normal use. Thepipets shall be free of strain when tested in accordance with6.4.5.7 IdentificationEach pipet shall have the name or reg-istered tradema
19、rk of the manufacturer. These markings are tobe located on the stem of the pipet directly opposite thegraduation lines. The manufacturer has the option to state thepipet volumetric tolerances on the pipet. These tolerances maybe located on the stem or the proximal end of the pipet.5.7.1 The white ce
20、ll pipet shall have a clear or white glassor ceramic bead sealed within the bulb to identify it readily asa white cell pipet.5.7.2 The red cell pipet shall have a red glass or ceramicbead sealed within the bulb to identify it readily as a red cellpipet.5.8 PigmentationAll markings shall be permanent
21、ly fusedin or on the pipet. The markings shall be dark amber or blackin color. When tested in accordance with 6.3, the pigmentationshall not discolor the solution. The appearance of the markings,when viewed by the eye under normal room lighting, shall bethe same after testing as before testing.6. Te
22、sting6.1 AccuracyAccuracy for these pipets shall be 65 % forred cell pipets and 63.5 % for white cell pipets. If V representsthe volume between the calibration lines immediately aboveand below the bulb, V1represents the volume of the capillarystem between the pipet tip and the calibration line numbe
23、red 1,and V2represents the volume of the capillary stem between thetip and the calibration line numbered 0.5, the volumetrictolerances shall be as stated in Specification E 694 and ex-pressed as follows:FIG. 1 Pipet DimensionsE 788 97 (2003)26.1.1 Red Cell PipetsNominal ratio 100:1V/V1shall not be l
24、ess than 95 or more than 105V/V2shall not be less than 190 or more than 2106.1.2 White Cell PipetsNominal ratio 10:1V/V1shall not be less than 9.65 or more than 10.35V/V2shall not be less than 19.30 or more than 20.706.2 Accuracy DeterminationV2, V1, and V shall be deter-mined by use of distilled wa
25、ter and a weighing device havinga weight sensitivity no less than 0.001 mg.6.2.1 The weight of a dry red or white cell pipet shall betaken first and recorded. This indication shall be subtractedfrom the weight indications of the red or white cell pipet filledwith distilled water to the lines numbere
26、d 0.5, 1, 101, or 11respectively. The weight of the water at temperature T,istobeconverted to volume at 20C. The net weight indicationsrepresent V2, V1, and V factors given in 6.1.1 and 6.1.2.6.3 Pigmentation TestFreshly prepare a chromic acidcleaning solution by combining 200 g of sodium dichromate
27、(Na2Cr2O72H2O), 1000 mL of water, and 1500 mL ofsulfuric acid (H2SO4, ACS Reagent 95 to 98 %). Immerse thepipets in the chromic acid solution. Let stand at room tempera-ture (20 to 25C) for 15 min. Remove the pipets from thesolution and thoroughly rinse in distilled water. Dry the pipetsby rubbing v
28、igorously, 5 to 10 strokes, with a laboratory clothor tissue. The appearance of the markings should be the sameas before the test, when judged by the eye under normal roomlighting.6.4 Strain-Free TestThe pipets shall be free from strainwhen viewed under a polariscope.6.5 For additional sampling and
29、testing data, see Specifica-tion E 1157.7. Packaging7.1 For packaging, select from either Specification E 920,Specification E 921, or Practice E 1133.8. Keywords8.1 blood; glass; pipetsFIG. 2 Permissible AlternativesE 788 97 (2003)3ASTM International takes no position respecting the validity of any
30、patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revis
31、ion at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your c
32、omments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrig
33、hted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E 788 97 (2003)4
