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Cell proliferation studies in primary synovial chondromatosis.

Primary synovial chondromatosis (PSC) is thought to be a cartilaginous metaplasia, but it may recur locally and malignant change has been reported. Histologically, the cartilage is usually cellular, with binucleate forms. These findings suggest that the disease is not simply a metaplasia but imply a proliferative component. In this study, immunohistochemical detection of Ki-67 protein using an antigen retrieval microwave heating technique and DNA image cytometry (VIDAS image analysis system) has been used to assess the proliferative activity in 20 cases of PSC and the results have been compared with those obtained in other cartilage tissues: ten enchondromas, ten chondrosarcomas, and ten samples of normal articular cartilage. There was no detectable staining for Ki-67 protein in cases of PSC or in benign tissues, but there was a significant association between Ki-67 labelling index and grade in the chondrosarcomas (P < 0.01). The absence of mitotic figures and the lack of Ki-67 protein in PSC are consistent with a metaplasia. All enchondromas gave diploid DNA histograms but non-diploid histograms were obtained i eight cases (40 per cent) of PSC, with significant populations of hyperdiploid and DNA aneuploid cells. The mean DNA content, the percentage of hyperdiploid cells, the percentage of DNA aneuploid cells, and the 2c deviation index were all significantly higher in PSC than in enchondromas (P < 0.01). These findings with image cytometry suggest a proliferative process in the development of at least some cases of PSC. In terms of cell proliferative activity, PSC appears to occupy a position which is intermediate between benign enchondromas and malignant chondrosarcomas, which may explain the aggressive clinical behaviour occasionally seen in this condition.

Bone Neoplasms↗

DNA quantification in colorectal carcinoma using flow and image analysis cytometry.

Numerous studies using flow cytometry (FCM) have shown that DNA quantification and ploidy classification can provide information of prognostic significance for patients with colorectal carcinoma; recent advances in image analysis cytometry (image cytometry, ICM) provide a new, alternative technique for DNA quantification. This study investigated whether (1) patients with colorectal carcinomas that exhibit a diploid pattern of DNA distribution have improved five-year survival statistics as compared to their non-diploid counterparts and (2) ICM provides quantitative data comparable to that obtained by FCM. DNA quantification and ploidy classification of 27 cases of primary colorectal carcinoma was performed on archival paraffin-embedded tissue by both FCM and ICM; 70% (19) of the tumors were classified as nondiploid by ICM while 56% (15) were similarly classified by FCM. Diploid tumors were associated with Dukes' stage A while nondiploid tumors were associated with Dukes' stage D. The overall five-year survival rate was 75% for patients with ICM diploid tumors and 67% for patients with FCM diploid tumors. The five-year survival was only 53% for patients with nondiploid tumors identified by both techniques. This study confirmed that DNA quantification is an important prognostic indicator for patients with colorectal carcinoma. It also showed that ICM provides data comparable to that of FCM and may be more sensitive.

Colorectal Neoplasms↗

Ploidy results in prostatic carcinoma vary with sampling method and with cytometric technique.

To evaluate the effect of sampling method and cytometric method on DNA ploidy results, a comparison study was performed on 20 whole prostate glands removed at prostatectomy. Fresh sampling was by sampling fine-needle aspiration (FNA). Paraffin sampling was by microdissection and re-embedding of 3 to 13 (average 6) 5-mm foci of microscopically proven tumor. Analysis was by flow cytometry and by image cytometry (microscopically guided). In tumor negative cases, flow and image cytometry of the FNA was diploid in each case, and flow cytometry of paraffin-embedded tissue was diploid in 5/6 cases. In tumor positive cases, non-diploid tumor was detected by image cytometry of the FNA in 70%, by flow cytometry of the FNA in 29%, and by flow cytometry of paraffin-extracted nuclei in 21%. The most effective combination was sampling fine-needle aspiration and image analysis.

Adenocarcinoma↗

Predictive value of DNA cytometry in CIN 1 and 2. Image analysis of 193 cases.

OBJECTIVE: To investigate DNA image cytometry for predicting the prognosis of cervical intraepithelial neoplasia (CIN). STUDY DESIGN: Smears from 151 women affected by CIN 1 or 2 on cytology with minimal follow-up of three years were included. Sixty-seven showed progression, with histologically confirmed carcinoma in situ or invasive cancer. Eighty-four cases showed regression of the disease, which was cytologically, histologically and colposcopically confirmed. Papanicolaou-stained smears were destained, and the Feulgen reaction was performed with consecutive image DNA cytometry of suspicious cells using an image analysis system (Cires, Zeiss, Germany). The DNA index of the greatest stemline and the number of single aneuploid cells, using 9c exceeding events, were computed. RESULTS: In the group with progression, an aneuploid DNA stemline was found in 25 smears (26.9%). In 64 cases (66.7%) more than one aneuploid event was detected. The total number of aneuploid cases in this group was 76 (81%). In the group without progression, the number of aneuploid stemlines was 2 (2%). Single aneuploid cells could be found in five cases (5%). The overall number of aneuploid cases in that group was five. The sensitivity was 74.3%, positive predictive value 85.2% and negative predictive value 77%. CONCLUSION: Aneuploidy is a marker for prospective malignancy in cervical Papanicolaou smears. DNA image cytometry, as an additional method, can be used to predict outcome in patients with CIN 1 and 2 of the cervix. DNA cytometry is not a screening method but can add further information for a treatment decision in doubtful cases.

Adult↗

The value of cytometric DNA analysis as a prognostic tool in neuroendocrine neoplastic diseases.

In several traditionally non-endocrine, common, human, neoplastic diseases, it has become well established during the last few years, that cytometric analyses of the DNA distribution pattern of the nuclei of tumour cells can be an excellent supplement to the conventional prognostic tools, (such as clinical staging and histopathologic malignancy assessments). When analogous studies of the value of DNA analysis by means of flow cytometry and/or image cytometry are made in neuroendocrine (NE) neoplastic diseases, the ensuing results often become rather disappointing. Thus, clear-cut aneuploid DNA histograms can be found in the neoplastic cell nuclei of clinically and histopathologically completely benign NE adenomas (and even hyperplastic nodules). In contrast, highly aggressive NE carcinomas not seldom reveal themselves to be composed of tumour cells with nuclei, displaying an euploid, i.e. normal, DNA pattern. Statements of this kind have been based on the results of comprehensive investigations in several laboratories, analysing such NE tumours as insulomas/insular carcinomas, bronchial/gastrointestinal carcinoids, phaeochromocytomas, paragangliomas, neuroblastomas, adenomas of the anterior pituitary gland, parathyroid adenomas, medullary carcinoma of the thyroid and Merkel-cell tumours of the skin. Thus, the prognostic value of the cytometric DNA ploidy pattern of the nuclei of neoplastic parenchymal cells is definitely lower in NE tumours than in most of the traditionally non-endocrine carcinomas and sarcomas. Data from published and unpublished series of these kinds of NE tumours, and those of prostatic and breast carcinomas with NE differentiation, are given. By means of a new, consecutive double staining technique, it was shown that in idiopathic nesidioblastosis, the hyperinsulinism is caused by beta cells with a nuclear DNA ploidy pattern of euploid type. By the same technique, it can be shown that in the pathogenesis of the hypergastrinaemia-induced ECL-cell carcinoids of the stomach, a switch from an euploid to an aneuploid nuclear DNA distribution pattern occurs in the ECL-cells when they pass from a state of hyperplasia to that of a genuine neoplasia. In neuroblastomas, a triploid (i.e. aneuploid) DNA pattern is part of an algorithm capable of predicting a 96% survival rate, whereas a diploid/tetraploid (i.e. euploid) DNA pattern predicts a 0% survival.

DNA, Neoplasm↗

Micronuclei assay by laser scanning cytometry.

BACKGROUND: The micronuclei (MN) assay is used to assess the chromosomal/mitotic spindle damage induced by ionizing radiation or mutagenic agents in vivo or in vitro. Because visual scoring of MN is cumbersome semi-automatic procedures that relay either on flow cytometry or image analysis were developed: both offer some advantages but also have shortcomings. METHODS: In the present study laser scanning cytometer (LSC), the instrument that combines analytical capabilities of flow and image cytometry, has been adapted for quantitative analysis of MN. The micronucleation of human breast carcinoma MCF-7 and leukemic HL-60 and U-937 cells was induced by in vitro treatment with mitomycin C. Cellular DNA was stained with propidium iodide (PI), protein was counterstained with fluorescein isothiocyanate (FITC). Two approaches were used to detect MN: (a) the threshold contour was set based on the data from the photosensor measuring red fluorescence of PI and MN were identified on the bivariate PI versus PI/FITC fluorescence distributions by their characteristic position; (b) the threshold contour was set on the data from the sensor measuring FITC fluorescence which made it possible, using the LSC software dedicated for FISH analysis, to assay both the frequency and DNA content of individual MN within each measured cell. RESULTS: The capability of LSC to relocate MN for visual examination was useful to confirm their identification. Visual identification of MN combined with their multiparameter characterization that took into an account their DNA content and protein/DNA ratio made it possible establish the gating parameters that excluded objects that were not MN; 93.3+/-3.3 events within the selected gate were MN. It was also possible to successfully apply FISH software to characterize individual cells with respect to quantity of MN residing in them. The percentage of MN assayed by LSC correlated well with that estimated visually by microscopy, both for MCF-7 (r = 0.93) and HL-60 cells (r = 0.87). CONCLUSIONS: LSC can be used to obtain unbiased estimate of MN frequencies. Unlike flow cytometry, it also allows one to characterize individual cells with respect to frequency and DNA content of MN residing in these cells. These analytical capabilities of LSC may be helpful not only to score MN but also to study mechanisms by which clastogenic agents induce MN.

Cell Count↗

Comparison of ploidy analysis by flow cytometry and image analysis in hydatidiform mole and non-molar abortion.

Determination of DNA ploidy is useful in the diagnosis and classification of hydatidiform mole. Most reports of ploidy analysis in molar tissue have used DNA flow cytometry. Although image analysis cytometry offers theoretical advantages over flow cytometry, there have been few reports of ploidy analysis by image analysis in hydatidiform mole. We selected 47 cases and measured DNA ploidy by flow cytometry and image analysis cytometry in complete hydatidiform mole, partial hydatidiform mole and non-molar abortion. The two cytometry modalities were compared using kappa statistics. There was reasonable overall agreement between the two modalities (kappa = 0.69) and when ploidy was stratified into diploid/polyploid and triploid categories there was near perfect agreement (kappa = 0.93). Aneuploid cell populations, which were not evident on flow cytometry, were identified by image analysis in a significant proportion of complete and partial hydatidiform moles and in a small number of non-molar abortions. Flow cytometry and image analysis cytometry yield comparable ploidy information, useful in the diagnosis and classification of hydatidiform mole. Image analysis cytometry offers greater sensitivity in the detection of small non-diploid cell populations but the significance of this latter finding is uncertain.

Abortion, Spontaneous↗

Morphometric characterization of endometrial glands using quantitative cytology.

OBJECTIVE: To determine the usefulness of the combination of confocal laser scanning microscopy (CLSM), image cytometry and three-dimensional (3D) imaging for analyzing architectural changes indicative of endometrial hyperplasia and grade 1 adenocarcinoma. STUDY DESIGN: Papanicolaou-stained endometrial samples (n = 180) were analyzed for specific cellular characteristics and analyzed by CLSM. Confocal images were obtained and then analyzed cytometrically and used for 3D reconstruction. RESULTS: Values obtained after image cytometry and 3D imaging increased significantly (P < .01) with the degree of cellular atypia. CONCLUSION: The combination of CLSM, image cytometry and 3D imaging is a valuable method for differential diagnosis of endometrial hyperplasia and grade 1 adenocarcinoma.

Adenocarcinoma↗

Image cytometric DNA analysis in transitional cell carcinoma of the bladder.

BACKGROUND: The current study was initiated to investigate measurable objective and reproducible characteristics that might have prognostic significance in bladder cancer. METHODS: Tumor samples from 91 patients with primary transitional cell carcinoma (TCC) of the urinary bladder were studied by DNA image cytometry and cytogenetic analysis. Image cytometry is a more sensitive method of determining ploidy than flow cytometry, especially in tumors with a low number of aneuploid cells. RESULTS: There was a significant difference in survival between DNA image cytometry-determined diploid and nondiploid cases. The presence of nuclei with a high DNA content indicated poor prognosis. The 2C deviation index (2CDI) also was an indicator of survival. Image cytometry-determined factors also were found to be strong predictors of progression-free survival. In multivariate analysis, 2CDI was the only cytometric parameter with an independent but weak correlation with survival. In multivariate analysis, none of the cytometric parameters had an important contribution to prediction of progression-free survival. In superficial tumors (Ta and T1), 2CDI appeared to be the most important independent predictor of survival. With respect to progression-free survival, tumors with a high mitotic index proved to have a worse prognosis. CONCLUSIONS: Parameters determined by DNA image cytometry appear to be valuable in predicting survival and progression-free survival and may be useful in addition to the classic parameters of stage and grade, especially in superficial TCC.

Adult↗

DNA ploidy of spindle cell soft-tissue tumors and its relationship to histology and clinical outcome.

With the use of fresh cell suspensions, the DNA ploidy of 11 benign and 27 malignant spindle cell soft-tissue lesions was determined by flow cytometry (37 cases) and/or image cytometry (35 cases). Of the 27 malignant lesions, 10 were low- or intermediate-grade sarcomas, and 17 were high-grade sarcomas. In the malignant lesions, the DNA ploidy was correlated with the histologic grade and the clinical outcome. Of the 11 benign lesions, six had a diploid DNA ploidy pattern, and five were nondiploid by either flow cytometry or image cytometry. All benign cases had a favorable outocome regardless of ploidy. Eight of the 10 low- or intermediate-grade malignant lesions were diploid, whereas two were nondiploid. Of the 17 high-grade sarcomas, 15 were nondiploid by either method of measurement and nine by both. Of the 10 diploid malignant tumors, only one had an unfavorable outcome (malignant mesothelioma with biopsy only), whereas of the 17 malignant lesions that were nondiploid, five had no evidence of recurrent disease, three cases recurred, eight patients died of disease, and one patient died of an unrelated cause. We concluded that (1) ploidy does not differentiate benign from malignant spindle cell soft-tissue tumors, (2) the nondiploid DNA pattern is more common in high-grade than in low- or intermediate-grade sarcomas, and (3) there is a statistically significant relationship between nondiploidy and a worse clinical outcome in sarcomas.

Adult↗

Interpretation guidelines of DNA histograms from tissue sections of breast cancer.

BACKGROUND: Evaluation of nuclear DNA staining intensity from histological breast cancer sections has not always been accepted, because of the difficulties in interpreting the histograms. One reason for this is the lack of evidence based interpretation guidelines. MATERIALS AND METHODS: The DNA staining intensity of 140 breast cancer samples was measured with flow cytometry (FCM) and image cytometry (ICM). The methods were compared by using grading efficiency (GE). RESULT: First, the ICM histograms were evaluated with a computer assisted image cytometry system using different cut off points for aneuploidy. The GE results varied from 67.9-76.4%. Subjective interpretation and evaluation according two previously published interpretation methods did not improve the GE. Secondly, we excluded histograms which showed clearly different cell clones in FCM and ICM. The GE of remaining histograms was 77.9%. Comparison of these histograms allowed formulation of interpretation guidelines which improved the GE to 85.3%. CONCLUSIONS: This study suggests that efficient interpretation guidelines of section-based DNA histograms can be created.

Aneuploidy↗

DNA quantitation of Wilms' tumour (nephroblastoma) using flow cytometry and image analysis.

AIMS: To compare flow cytometry (FCM) with image analysis (IA) in the DNA quantitation of Wilms' tumour (WT) and to correlate data so obtained with recognised clinical and pathological prognostic parameters. METHODS: Thirty six patients with histologically proved WT diagnosed between 1980-89 were investigated. Fifteen patients had stage I disease, 10 stage II, six stage III, two stage IV and three stage V. Suspension of nuclei obtained by pepsin digestion of paraffin wax embedded tumour tissue was analysed using a FAC-Scan flow cytometer, and a CAS-100 image analyser. RESULTS: Tumours were concordant in most instances, however, IA identified aneuploidy in two tumour samples which were diploid by FCM. Aneuploidy was detected in 5/33 tumours with favourable histology and 3/3 with unfavourable histology. Three of 28 patients with Stage I, II and V disease and 5/8 patients with stage III and IV had aneuploid tumours. All patients with unfavourable histology died of disease. In the group with favourable histology, 4/5 patients with aneuploid tumours developed recurrent disease compared with 1/27 diploid tumours (p less than 0.0001). CONCLUSIONS: Ploidy may be a useful additional prognostic indicator in Wilms' tumour with favourable histology. Larger scale studies are needed to confirm the relation of ploidy to survival in early stage WT.

Child↗

Flow and image cytometric DNA analysis of postcardiac transplant lymphomas.

Organ transplant recipients and other immunodeficient individuals are at risk for the development of Epstein-Barr virus-related B-cell lymphomas. The incidence of lymphoma after cardiac transplantation ranges from 2 to 11%. To determine whether the clinical presentation, histological subtype, or clinical outcome correlated with DNA content, 17 patients with postcardiac transplant lymphoma were studied by flow and image cytometry. Their mean age was 52 yr (range: 33 to 67 yr) with a mean interval of 10 mo (range: 0.5 to 50 mo) between the time of transplantation and the diagnosis of lymphoma. Of the 17 specimens analyzed by flow cytometry, 14 (82%) were diploid and 3 (18%) aneuploid. By image cytometry, 15 (88%) were diploid and 2 (12%) aneuploid. Agreement between flow cytometry and image cytometry was 94%. No statistically significant correlation between DNA content (ploidy and % S-phase fraction) and the interval since transplantation, histological subtype, or clinical outcome could be determined. A rate of DNA aneuploidy was seen that was lower than previously reported for lymphomas with the same histological grade and cell proliferation rate occurring in immunocompetent individuals. These findings are similar to those reported for AIDS-related lymphomas.

Adult↗

Evaluation of tumor heterogeneity of prostate carcinoma by flow- and image DNA cytometry and histopathological grading.

BACKGROUND: Heterogeneity of prostate carcinoma is one of the reasons for pretreatment underestimation of tumor aggressiveness. We studied tumor heterogeneity and the probability of finding the highest tumor grade and DNA aneuploidy with relation to the number of biopsies. MATERIAL AND METHODS: Specimens simulating core biopsies from five randomly selected tumor areas from each of 16 Böcking's grade II and 23 grade III prostate carcinomas were analyzed for tumor grade and DNA ploidy by flow- and fluorescence image cytometry (FCM, FICM). Cell cycle composition was measured by FCM. RESULTS: By determination of ploidy and cell cycle composition, morphologically defined tumors can further be subdivided. Heterogeneity of tumor grade and DNA ploidy (FCM) was 54% and 50%. Coexistence of diploid tumor cells in aneuploid specimens represents another form of tumor heterogeneity. The proportion of diploid tumor cells decreased significantly with tumor grade and with increase in the fraction of proliferating cell of the aneuploid tumor part. The probability of estimating the highest tumor grade or aneuploidy increased from 40% for one biopsy to 95% for 5 biopsies studied. By combining the tumor grade with DNA ploidy, the probability of detecting a highly aggressive tumor increased from 40% to 70% and 90% for one and two biopsies, respectively. CONCLUSION: Specimens of the size of core biopsies can be used for evaluation of DNA ploidy and cell cycle composition. Underestimation of aggressiveness of prostate carcinoma due to tumor heterogeneity is minimized by simultaneous study of the tumor grade and DNA ploidy more than by increasing the number of biopsies. The biological significance of coexistent diploid tumor cell in aneuploid lesions remains to be evaluated.

Biopsy↗

Digital image DNA cytometry: a useful tool for the evaluation of malignancy in biliary strictures.

BACKGROUND: Cytologic evaluation of the biliary tract strictures is nowadays widely used for distinguishing between benign and malignant lesions but remains a challenge for some problematic cases. Digital Image cytometry (DNA-cytometry) helps cytopathologists to resolve some unclear situations. METHODS: We have analysed 41 specimens of bile duct brushings obtained from patients during ERCP (11 benign cases, 7 suspicious for malignancy cases and 23 malignant cases) by DNA-cytometry and correlated them with the histological biopsy counterpart. RESULTS: All eleven cytological and histological benign cases were DNA-diploid and among 22 patients with malignant cytological and histological diagnosis 21 were DNA-aneuploid. One case considered malignant by the cytopathologist revealed DNA-aneuploid but malignancy could not be confirmed by histology. The analysis of the suspicious for malignancy cases revealed that all DNA-aneuploid cases were malignant and all DNA-diploid cases were benign referring to the follow-up of the patients. The comparison between cytology alone and cytology combined with DNA-cytometry related to the histological diagnosis (gold standard) resulted in a sensitivity of 100% and a specificity of 79% for cytology alone; a specificity of 94% and a sensitivity 92% for DNA-cytometry and a specificity of 93% and a sensitivity of 100% with combined analyses. The positive predictive value was 90% for cytology, 96% for DNA-cytometry and for both analyses. The negative predictive value showed 100% for cytology, 89% for DNA-cytometry and 100% for combined studies. CONCLUSIONS: Despite the limited number of patients involved in the study, the results obtained indicate an increased of specificity and of positive predictive value using DNA-cytometry. These results confirm the pertinence of these method for challenging cases, in conjunction with other available diagnostic tools.

Adult↗

Image and flow cytometric analyses of DNA content in human solid tumors. A comparative study.

OBJECTIVE: To compare the sensitivity and potentials of flow and image cytometry in assessing DNA content. STUDY DESIGN: The study was performed on 152 tumors (oral cavity, uterine cervix, bladder, colorectum, breast). Flow cytometry was carried out on cell suspensions from frozen samples, and the results were expressed as the DNA index. Image cytometry was performed on Feulgen-stained sections, and the results were expressed as the rate of cells exceeding 2.5c or 5c. For colorectal and breast cancers, DNA content by image cytometry was also measured on imprints and was expressed as the DNA index or rate of cells exceeding 2.5c and 5c. RESULTS: Among flow cytometric diploid tumors, image cytometric analysis performed on histologic sections showed about 80% diploid tumors from the uterine cervix and breast cancers. The frequency decreased to 36% for oral cavity cancers. Generally satisfactory concordance was observed when flow cytometric aneuploid tumors were analyzed. A highly significant correlation was observed between DNA indices observed by flow and image cytometry on imprints. CONCLUSION: Image cytometry appears more sensitive than flow cytometry in detecting small, aneuploid clones, but its main limitation is the low power in resolving near-diploid cell populations. The results on imprints indicate that image cytometry is a potential alternative approach for small tumor samples.

Adenocarcinoma↗

Discrimination between chronic pancreatitis and pancreatic adenocarcinoma using artificial intelligence-related algorithms based on image cytometry-generated variables.

The incidence of pancreatic adenocarcinomas (PA) is increased in the setting of chronic pancreatitis. Distinguishing chronic pancreatitis from pancreatic adenocarcinomas is often difficult, and is based on routine brush cytological specimens provided during endoscopic retrograde cholangiopancreatography (ERCP). Reactive epithelial changes in chronic pancreatitis may appear similar to those of a well-differentiated cancer. Brush cytology specimens were obtained during ERCP from 49 patients with diseases for which the differential diagnosis included chronic pancreatitis and/or pancreatic adenocarcinoma Image cytometry was performed involving the assessment of between 200-400 Feulgen-stained nuclei per case; for each case, 40 quantitative cytometric variables were generated. Data analysis was performed using artificial intelligence methods of data classification that produced decision trees and production rule systems. Different classification models were produced for a subset of 34 patients. The best models were identified by the use of a sampling technique (leave-one-out), and were tested on the remaining 15 patients. These models were based on 5 of the 40 variables associated with a significant discriminatory function. Pancreatic adenocarcinoma was diagnosed in the training data set of 34 patients during a leave-one-out process with an estimated sensitivity of 91% and specificity of 87%. Both sensitivity and specificity were 80% in the independent test set of 15 patients. We conclude that inflammatory and malignant pancreatic epithelia exhibit distinct morphological features that can be distinguished by decision tree-based classifiers employing image-cytometric numerical data.

Adenocarcinoma↗

Fast imaging in flow: a means of combining flow-cytometry and image analysis.

The morphological identification of cells by flow cytometry is difficult. Usually cell sorting and microscopical analysis have to be used in addition. Morphological analysis is simplified by taking cell pictures from a range of particular interest immediately during flow cytometric analysis. Instruments using the video scanning technique for fluorescence imaging are slow and expensive (8, 10). Morphological information can also be obtained by transmission imaging of cells in flow, which requires shorter exposure times. Therefore a cell volume activated flow imaging device has been developed which operates at flow speeds up to 5 m/sec and which depicts transmission images of selected cells on a 16-mm film by a nsec flashlamp illumination. An electronic unit detects the particles in the optically accessible orifice, performs the pulse height analysis, triggers the flashlamp if particles are in the preselcted range of interest and feeds the film. The instrument is capable of delivering up to 150 pictures per second and works either as a flow microscope in which the cells in the preselected volume range are directly observed, or as a picture system in which the cell pictures are stored on the 16-mm film for documentation or for image analysis.

Cell Count↗