Dry Blood

Blood for Serologic Examinations

dryblood — Sat, 19 May 2007 16:50:37 +0000

Blood cultures

dryblood — Sat, 19 May 2007 16:36:08 +0000

A specimen for microscopic examination with the use of compound microscope is blood. Blood for cultures must be collected with special care because microbes, especially staphylococci, are present on the surface of the skin and within its superficial layers.

A blood culture is usually taken by venipuncture. Venipuncture is done first by painting the skin over the veins in the bend of the elbow with tincture of iodine or other suitable disinfectant like 70 percent alcohol. Some persons may be allergic to iodine. Make a second application of tincture of iodine or 70 percent alcohol to thoroughly sterilize the area. Then compress the area. Secure a tourniquet, but not too tightly, around the arm just above the elbow. Ask the patient to close and open the hand several times.

Puncture a prominent vein with the use of a 20 or 21 gauge needle to which may be attached a 20 ml. syringe or vacutainer. Vacutainer is a specially designed holder for a vacuum tube. Withdraw from 10 to 15 ml. of blood or whatever amount is indicated for the particular laboratory test.

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Diagnosis From the Blood Smear

dryblood — Mon, 14 May 2007 02:13:53 +0000

An examination of the blood smear may be requested by physicians or initiated by laboratory staff. With the development of sophisticated automated blood-cell analyzers, the proportion of blood-count samples that require a blood smear has steadily diminished and in many clinical settings is now 10 to 15 percent or less. Nevertheless, the blood smear remains a crucial diagnostic aid. The proportion of requests for a complete blood count that generate a blood smear is determined by local policies and sometimes by financial and regulatory as well as medical considerations. For maximal information to be derived from a blood smear, the examination should be performed by an experienced and skilled person, either a laboratory scientist or a medically qualified hematologist or pathologist. In Europe, only laboratory-trained staff members generally read or examine a blood smear, whereas in the United States, physicians have often done this.

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Dry Blood Smear Preparation to Identify Babesia Organism

dryblood — Mon, 14 May 2007 02:13:17 +0000

Babesia and its close relatives are members of a group of organisms called piroplasms, a name which comes from their pear-shaped outlines. Long associated with blood diseases of cattle and other mammals, members of the genus Babesia have been recognized since the 1950s as infectious agents in humans. Species of this protozoan blood parasite that have routinely been isolated from mice B. microti or cattle B. divergens have also been isolated from humans. In addition to these familiar species, new isolates that resist being placed in existing taxonomic categories are the basis for rethinking their phylogenetic relationships based on sequencing data. The parasite represents a threat to the safety of the blood supply in that blood from asymptomatic humans can transmit Babesia to blood recipients. Such transmissions have occurred.

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Dry Blood Smear Description

dryblood — Mon, 14 May 2007 02:11:38 +0000

A blood smear allows the evaluation of white blood cells, red blood cells and platelets. These cell populations are created by and matured in the bone marrow and released into the bloodstream as required. WBC or White Blood Cell is used by the body to fight infection, RBC or Red Blood Cell to carry oxygen to the different organs of the human body and Platelets or Thrombocytes to help clot the blood. The number and type of each cell present in the blood is dynamic, maintained by the body within normal ranges, but fluctuating slightly all the time, depending on the needs of the body. A peripheral blood smear is a snapshot of the cells that are present in the blood at the time that the sample is obtained. To create a blood smear, a single drop of blood is spread in a thin layer across a glass slide, dried, and then stained with a special dye. Once the stain has dried the slide is evaluated under a microscope by laboratory personnel.

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